DialogBoxParamW

// USER32.dll  (Unicode / -W)
#include <windows.h>

INT_PTR DialogBoxParamW(
    HINSTANCE hInstance,   // optional
    LPCWSTR lpTemplateName,
    HWND hWndParent,   // optional
    DLGPROC lpDialogFunc,   // optional
    LPARAM dwInitParam
);

<DllImport("USER32.dll", CharSet:=CharSet.Unicode, SetLastError:=True, ExactSpelling:=True)>
Public Shared Function DialogBoxParamW(
    hInstance As IntPtr,   ' HINSTANCE optional
    <MarshalAs(UnmanagedType.LPWStr)> lpTemplateName As String,   ' LPCWSTR
    hWndParent As IntPtr,   ' HWND optional
    lpDialogFunc As IntPtr,   ' DLGPROC optional
    dwInitParam As IntPtr   ' LPARAM
) As IntPtr
End Function

' hInstance : HINSTANCE optional
' lpTemplateName : LPCWSTR
' hWndParent : HWND optional
' lpDialogFunc : DLGPROC optional
' dwInitParam : LPARAM
Declare PtrSafe Function DialogBoxParamW Lib "user32" ( _
    ByVal hInstance As LongPtr, _
    ByVal lpTemplateName As LongPtr, _
    ByVal hWndParent As LongPtr, _
    ByVal lpDialogFunc As LongPtr, _
    ByVal dwInitParam As LongPtr) As LongPtr
' Unicode(W): 文字列は ByVal As LongPtr とし StrPtr(unicodeStr) を渡す
' VBA7前提(PtrSafe)。32bit Office では LongPtr→Long。Integer=16bit / Long=32bit / LongLong=64bit。

import ctypes
from ctypes import wintypes

DialogBoxParamW = ctypes.windll.user32.DialogBoxParamW
DialogBoxParamW.restype = ctypes.c_ssize_t
DialogBoxParamW.argtypes = [
    wintypes.HANDLE,  # hInstance : HINSTANCE optional
    wintypes.LPCWSTR,  # lpTemplateName : LPCWSTR
    wintypes.HANDLE,  # hWndParent : HWND optional
    ctypes.c_void_p,  # lpDialogFunc : DLGPROC optional
    ctypes.c_ssize_t,  # dwInitParam : LPARAM
]
# GetLastError: use ctypes.GetLastError() (or ctypes.WinDLL(use_last_error=True))

require 'fiddle'
require 'fiddle/import'

lib = Fiddle.dlopen('USER32.dll')
DialogBoxParamW = Fiddle::Function.new(
  lib['DialogBoxParamW'],
  [
    Fiddle::TYPE_VOIDP,  # hInstance : HINSTANCE optional
    Fiddle::TYPE_VOIDP,  # lpTemplateName : LPCWSTR
    Fiddle::TYPE_VOIDP,  # hWndParent : HWND optional
    Fiddle::TYPE_VOIDP,  # lpDialogFunc : DLGPROC optional
    Fiddle::TYPE_INTPTR_T,  # dwInitParam : LPARAM
  ],
  Fiddle::TYPE_INTPTR_T)
# Wide strings: pass str.encode("UTF-16LE") + "\x00\x00"

#[link(name = "user32")]
extern "system" {
    fn DialogBoxParamW(
        hInstance: *mut core::ffi::c_void,  // HINSTANCE optional
        lpTemplateName: *const u16,  // LPCWSTR
        hWndParent: *mut core::ffi::c_void,  // HWND optional
        lpDialogFunc: *const core::ffi::c_void,  // DLGPROC optional
        dwInitParam: isize  // LPARAM
    ) -> isize;
}
// crates: windows-sys provides ready-made bindings for this API.

$sig = @"
[DllImport("USER32.dll", CharSet = CharSet.Unicode, SetLastError = true)]
public static extern IntPtr DialogBoxParamW(IntPtr hInstance, [MarshalAs(UnmanagedType.LPWStr)] string lpTemplateName, IntPtr hWndParent, IntPtr lpDialogFunc, IntPtr dwInitParam);
"@
$api = Add-Type -MemberDefinition $sig -Name 'USER32_DialogBoxParamW' -Namespace Win32 -PassThru
# $api::DialogBoxParamW(hInstance, lpTemplateName, hWndParent, lpDialogFunc, dwInitParam)

#uselib "USER32.dll"
#func global DialogBoxParamW "DialogBoxParamW" wptr, wptr, wptr, wptr, wptr
; DialogBoxParamW hInstance, lpTemplateName, hWndParent, lpDialogFunc, dwInitParam   ; 戻り値は stat
; hInstance : HINSTANCE optional -> "wptr"
; lpTemplateName : LPCWSTR -> "wptr"
; hWndParent : HWND optional -> "wptr"
; lpDialogFunc : DLGPROC optional -> "wptr"
; dwInitParam : LPARAM -> "wptr"
; ※HSP3.7は #func のため戻り値はシステム変数 stat に格納されます。

#uselib "USER32.dll"
#cfunc global DialogBoxParamW "DialogBoxParamW" sptr, wstr, sptr, sptr, sptr
; res = DialogBoxParamW(hInstance, lpTemplateName, hWndParent, lpDialogFunc, dwInitParam)
; hInstance : HINSTANCE optional -> "sptr"
; lpTemplateName : LPCWSTR -> "wstr"
; hWndParent : HWND optional -> "sptr"
; lpDialogFunc : DLGPROC optional -> "sptr"
; dwInitParam : LPARAM -> "sptr"

; INT_PTR DialogBoxParamW(HINSTANCE hInstance, LPCWSTR lpTemplateName, HWND hWndParent, DLGPROC lpDialogFunc, LPARAM dwInitParam)
#uselib "USER32.dll"
#cfunc global DialogBoxParamW "DialogBoxParamW" intptr, wstr, intptr, intptr, intptr
; res = DialogBoxParamW(hInstance, lpTemplateName, hWndParent, lpDialogFunc, dwInitParam)
; hInstance : HINSTANCE optional -> "intptr"
; lpTemplateName : LPCWSTR -> "wstr"
; hWndParent : HWND optional -> "intptr"
; lpDialogFunc : DLGPROC optional -> "intptr"
; dwInitParam : LPARAM -> "intptr"

import (
	"golang.org/x/sys/windows"
	"unsafe"
)

var (
	user32 = windows.NewLazySystemDLL("USER32.dll")
	procDialogBoxParamW = user32.NewProc("DialogBoxParamW")
)

// hInstance (HINSTANCE optional), lpTemplateName (LPCWSTR), hWndParent (HWND optional), lpDialogFunc (DLGPROC optional), dwInitParam (LPARAM)
r1, _, err := procDialogBoxParamW.Call(
	uintptr(hInstance),
	uintptr(unsafe.Pointer(windows.StringToUTF16Ptr(lpTemplateName))),
	uintptr(hWndParent),
	uintptr(lpDialogFunc),
	uintptr(dwInitParam),
)
_ = err  // syscall.Errno (valid when the call sets last-error)
_ = r1   // INT_PTR

function DialogBoxParamW(
  hInstance: THandle;   // HINSTANCE optional
  lpTemplateName: PWideChar;   // LPCWSTR
  hWndParent: THandle;   // HWND optional
  lpDialogFunc: Pointer;   // DLGPROC optional
  dwInitParam: NativeInt   // LPARAM
): NativeInt; stdcall;
  external 'USER32.dll' name 'DialogBoxParamW';

result := DllCall("USER32\DialogBoxParamW"
    , "Ptr", hInstance   ; HINSTANCE optional
    , "WStr", lpTemplateName   ; LPCWSTR
    , "Ptr", hWndParent   ; HWND optional
    , "Ptr", lpDialogFunc   ; DLGPROC optional
    , "Ptr", dwInitParam   ; LPARAM
    , "Ptr")   ; return: INT_PTR

●DialogBoxParamW(hInstance, lpTemplateName, hWndParent, lpDialogFunc, dwInitParam) = DLL("USER32.dll", "int DialogBoxParamW(void*, char*, void*, void*, int)")
# 呼び出し: DialogBoxParamW(hInstance, lpTemplateName, hWndParent, lpDialogFunc, dwInitParam)
# hInstance : HINSTANCE optional -> "void*"
# lpTemplateName : LPCWSTR -> "char*"
# hWndParent : HWND optional -> "void*"
# lpDialogFunc : DLGPROC optional -> "void*"
# dwInitParam : LPARAM -> "int"
# なでしこ1は32bit・ANSI(Shift_JIS)。文字列=char*(ANSI)、ポインタ/ハンドル=void*(4byte)。
# ※-W(Unicode)関数。なでしこ1はANSIのため -A 版の利用を推奨。