SHRegGetPathW

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

WIN32_ERROR SHRegGetPathW(
    HKEY hKey,
    LPCWSTR pcszSubKey,   // optional
    LPCWSTR pcszValue,   // optional
    LPWSTR pszPath,
    DWORD dwFlags
);

<DllImport("SHLWAPI.dll", CharSet:=CharSet.Unicode, ExactSpelling:=True)>
Public Shared Function SHRegGetPathW(
    hKey As IntPtr,   ' HKEY
    <MarshalAs(UnmanagedType.LPWStr)> pcszSubKey As String,   ' LPCWSTR optional
    <MarshalAs(UnmanagedType.LPWStr)> pcszValue As String,   ' LPCWSTR optional
    <MarshalAs(UnmanagedType.LPWStr)> pszPath As System.Text.StringBuilder,   ' LPWSTR out
    dwFlags As UInteger   ' DWORD
) As UInteger
End Function

' hKey : HKEY
' pcszSubKey : LPCWSTR optional
' pcszValue : LPCWSTR optional
' pszPath : LPWSTR out
' dwFlags : DWORD
Declare PtrSafe Function SHRegGetPathW Lib "shlwapi" ( _
    ByVal hKey As LongPtr, _
    ByVal pcszSubKey As LongPtr, _
    ByVal pcszValue As LongPtr, _
    ByVal pszPath As LongPtr, _
    ByVal dwFlags As Long) As Long
' 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

SHRegGetPathW = ctypes.windll.shlwapi.SHRegGetPathW
SHRegGetPathW.restype = wintypes.DWORD
SHRegGetPathW.argtypes = [
    wintypes.HANDLE,  # hKey : HKEY
    wintypes.LPCWSTR,  # pcszSubKey : LPCWSTR optional
    wintypes.LPCWSTR,  # pcszValue : LPCWSTR optional
    wintypes.LPWSTR,  # pszPath : LPWSTR out
    wintypes.DWORD,  # dwFlags : DWORD
]

require 'fiddle'
require 'fiddle/import'

lib = Fiddle.dlopen('SHLWAPI.dll')
SHRegGetPathW = Fiddle::Function.new(
  lib['SHRegGetPathW'],
  [
    Fiddle::TYPE_VOIDP,  # hKey : HKEY
    Fiddle::TYPE_VOIDP,  # pcszSubKey : LPCWSTR optional
    Fiddle::TYPE_VOIDP,  # pcszValue : LPCWSTR optional
    Fiddle::TYPE_VOIDP,  # pszPath : LPWSTR out
    -Fiddle::TYPE_INT,  # dwFlags : DWORD
  ],
  -Fiddle::TYPE_INT)
# Wide strings: pass str.encode("UTF-16LE") + "\x00\x00"

#[link(name = "shlwapi")]
extern "system" {
    fn SHRegGetPathW(
        hKey: *mut core::ffi::c_void,  // HKEY
        pcszSubKey: *const u16,  // LPCWSTR optional
        pcszValue: *const u16,  // LPCWSTR optional
        pszPath: *mut u16,  // LPWSTR out
        dwFlags: u32  // DWORD
    ) -> u32;
}
// crates: windows-sys provides ready-made bindings for this API.

$sig = @"
[DllImport("SHLWAPI.dll", CharSet = CharSet.Unicode)]
public static extern uint SHRegGetPathW(IntPtr hKey, [MarshalAs(UnmanagedType.LPWStr)] string pcszSubKey, [MarshalAs(UnmanagedType.LPWStr)] string pcszValue, [MarshalAs(UnmanagedType.LPWStr)] System.Text.StringBuilder pszPath, uint dwFlags);
"@
$api = Add-Type -MemberDefinition $sig -Name 'SHLWAPI_SHRegGetPathW' -Namespace Win32 -PassThru
# $api::SHRegGetPathW(hKey, pcszSubKey, pcszValue, pszPath, dwFlags)

#uselib "SHLWAPI.dll"
#func global SHRegGetPathW "SHRegGetPathW" wptr, wptr, wptr, wptr, wptr
; SHRegGetPathW hKey, pcszSubKey, pcszValue, varptr(pszPath), dwFlags   ; 戻り値は stat
; hKey : HKEY -> "wptr"
; pcszSubKey : LPCWSTR optional -> "wptr"
; pcszValue : LPCWSTR optional -> "wptr"
; pszPath : LPWSTR out -> "wptr"
; dwFlags : DWORD -> "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 "SHLWAPI.dll"
#cfunc global SHRegGetPathW "SHRegGetPathW" sptr, wstr, wstr, var, int
; res = SHRegGetPathW(hKey, pcszSubKey, pcszValue, pszPath, dwFlags)
; hKey : HKEY -> "sptr"
; pcszSubKey : LPCWSTR optional -> "wstr"
; pcszValue : LPCWSTR optional -> "wstr"
; pszPath : LPWSTR out -> "var"
; dwFlags : DWORD -> "int"
; ※出力/バッファ引数は var 方式(変数を直接渡す)。varptr 方式にも切替可。

; WIN32_ERROR SHRegGetPathW(HKEY hKey, LPCWSTR pcszSubKey, LPCWSTR pcszValue, LPWSTR pszPath, DWORD dwFlags)
#uselib "SHLWAPI.dll"
#cfunc global SHRegGetPathW "SHRegGetPathW" intptr, wstr, wstr, var, int
; res = SHRegGetPathW(hKey, pcszSubKey, pcszValue, pszPath, dwFlags)
; hKey : HKEY -> "intptr"
; pcszSubKey : LPCWSTR optional -> "wstr"
; pcszValue : LPCWSTR optional -> "wstr"
; pszPath : LPWSTR out -> "var"
; dwFlags : DWORD -> "int"
; ※出力/バッファ引数は var 方式(変数を直接渡す)。varptr 方式にも切替可。

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

var (
	shlwapi = windows.NewLazySystemDLL("SHLWAPI.dll")
	procSHRegGetPathW = shlwapi.NewProc("SHRegGetPathW")
)

// hKey (HKEY), pcszSubKey (LPCWSTR optional), pcszValue (LPCWSTR optional), pszPath (LPWSTR out), dwFlags (DWORD)
r1, _, err := procSHRegGetPathW.Call(
	uintptr(hKey),
	uintptr(unsafe.Pointer(windows.StringToUTF16Ptr(pcszSubKey))),
	uintptr(unsafe.Pointer(windows.StringToUTF16Ptr(pcszValue))),
	uintptr(pszPath),
	uintptr(dwFlags),
)
_ = err  // syscall.Errno (valid when the call sets last-error)
_ = r1   // WIN32_ERROR

function SHRegGetPathW(
  hKey: THandle;   // HKEY
  pcszSubKey: PWideChar;   // LPCWSTR optional
  pcszValue: PWideChar;   // LPCWSTR optional
  pszPath: PWideChar;   // LPWSTR out
  dwFlags: DWORD   // DWORD
): DWORD; stdcall;
  external 'SHLWAPI.dll' name 'SHRegGetPathW';

result := DllCall("SHLWAPI\SHRegGetPathW"
    , "Ptr", hKey   ; HKEY
    , "WStr", pcszSubKey   ; LPCWSTR optional
    , "WStr", pcszValue   ; LPCWSTR optional
    , "Ptr", pszPath   ; LPWSTR out
    , "UInt", dwFlags   ; DWORD
    , "UInt")   ; return: WIN32_ERROR

●SHRegGetPathW(hKey, pcszSubKey, pcszValue, pszPath, dwFlags) = DLL("SHLWAPI.dll", "dword SHRegGetPathW(void*, char*, char*, char*, dword)")
# 呼び出し: SHRegGetPathW(hKey, pcszSubKey, pcszValue, pszPath, dwFlags)
# hKey : HKEY -> "void*"
# pcszSubKey : LPCWSTR optional -> "char*"
# pcszValue : LPCWSTR optional -> "char*"
# pszPath : LPWSTR out -> "char*"
# dwFlags : DWORD -> "dword"
# 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。