SHSetValueW

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

INT SHSetValueW(
    HKEY hkey,
    LPCWSTR pszSubKey,   // optional
    LPCWSTR pszValue,   // optional
    DWORD dwType,
    const void* pvData,   // optional
    DWORD cbData
);

<DllImport("SHLWAPI.dll", CharSet:=CharSet.Unicode, ExactSpelling:=True)>
Public Shared Function SHSetValueW(
    hkey As IntPtr,   ' HKEY
    <MarshalAs(UnmanagedType.LPWStr)> pszSubKey As String,   ' LPCWSTR optional
    <MarshalAs(UnmanagedType.LPWStr)> pszValue As String,   ' LPCWSTR optional
    dwType As UInteger,   ' DWORD
    pvData As IntPtr,   ' void* optional
    cbData As UInteger   ' DWORD
) As Integer
End Function

' hkey : HKEY
' pszSubKey : LPCWSTR optional
' pszValue : LPCWSTR optional
' dwType : DWORD
' pvData : void* optional
' cbData : DWORD
Declare PtrSafe Function SHSetValueW Lib "shlwapi" ( _
    ByVal hkey As LongPtr, _
    ByVal pszSubKey As LongPtr, _
    ByVal pszValue As LongPtr, _
    ByVal dwType As Long, _
    ByVal pvData As LongPtr, _
    ByVal cbData 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

SHSetValueW = ctypes.windll.shlwapi.SHSetValueW
SHSetValueW.restype = ctypes.c_int
SHSetValueW.argtypes = [
    wintypes.HANDLE,  # hkey : HKEY
    wintypes.LPCWSTR,  # pszSubKey : LPCWSTR optional
    wintypes.LPCWSTR,  # pszValue : LPCWSTR optional
    wintypes.DWORD,  # dwType : DWORD
    ctypes.POINTER(None),  # pvData : void* optional
    wintypes.DWORD,  # cbData : DWORD
]

require 'fiddle'
require 'fiddle/import'

lib = Fiddle.dlopen('SHLWAPI.dll')
SHSetValueW = Fiddle::Function.new(
  lib['SHSetValueW'],
  [
    Fiddle::TYPE_VOIDP,  # hkey : HKEY
    Fiddle::TYPE_VOIDP,  # pszSubKey : LPCWSTR optional
    Fiddle::TYPE_VOIDP,  # pszValue : LPCWSTR optional
    -Fiddle::TYPE_INT,  # dwType : DWORD
    Fiddle::TYPE_VOIDP,  # pvData : void* optional
    -Fiddle::TYPE_INT,  # cbData : DWORD
  ],
  Fiddle::TYPE_INT)
# Wide strings: pass str.encode("UTF-16LE") + "\x00\x00"

#[link(name = "shlwapi")]
extern "system" {
    fn SHSetValueW(
        hkey: *mut core::ffi::c_void,  // HKEY
        pszSubKey: *const u16,  // LPCWSTR optional
        pszValue: *const u16,  // LPCWSTR optional
        dwType: u32,  // DWORD
        pvData: *const (),  // void* optional
        cbData: u32  // DWORD
    ) -> i32;
}
// crates: windows-sys provides ready-made bindings for this API.

$sig = @"
[DllImport("SHLWAPI.dll", CharSet = CharSet.Unicode)]
public static extern int SHSetValueW(IntPtr hkey, [MarshalAs(UnmanagedType.LPWStr)] string pszSubKey, [MarshalAs(UnmanagedType.LPWStr)] string pszValue, uint dwType, IntPtr pvData, uint cbData);
"@
$api = Add-Type -MemberDefinition $sig -Name 'SHLWAPI_SHSetValueW' -Namespace Win32 -PassThru
# $api::SHSetValueW(hkey, pszSubKey, pszValue, dwType, pvData, cbData)

#uselib "SHLWAPI.dll"
#func global SHSetValueW "SHSetValueW" wptr, wptr, wptr, wptr, wptr, wptr
; SHSetValueW hkey, pszSubKey, pszValue, dwType, pvData, cbData   ; 戻り値は stat
; hkey : HKEY -> "wptr"
; pszSubKey : LPCWSTR optional -> "wptr"
; pszValue : LPCWSTR optional -> "wptr"
; dwType : DWORD -> "wptr"
; pvData : void* optional -> "wptr"
; cbData : 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 SHSetValueW "SHSetValueW" sptr, wstr, wstr, int, sptr, int
; res = SHSetValueW(hkey, pszSubKey, pszValue, dwType, pvData, cbData)
; hkey : HKEY -> "sptr"
; pszSubKey : LPCWSTR optional -> "wstr"
; pszValue : LPCWSTR optional -> "wstr"
; dwType : DWORD -> "int"
; pvData : void* optional -> "sptr"
; cbData : DWORD -> "int"

; INT SHSetValueW(HKEY hkey, LPCWSTR pszSubKey, LPCWSTR pszValue, DWORD dwType, void* pvData, DWORD cbData)
#uselib "SHLWAPI.dll"
#cfunc global SHSetValueW "SHSetValueW" intptr, wstr, wstr, int, intptr, int
; res = SHSetValueW(hkey, pszSubKey, pszValue, dwType, pvData, cbData)
; hkey : HKEY -> "intptr"
; pszSubKey : LPCWSTR optional -> "wstr"
; pszValue : LPCWSTR optional -> "wstr"
; dwType : DWORD -> "int"
; pvData : void* optional -> "intptr"
; cbData : DWORD -> "int"

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

var (
	shlwapi = windows.NewLazySystemDLL("SHLWAPI.dll")
	procSHSetValueW = shlwapi.NewProc("SHSetValueW")
)

// hkey (HKEY), pszSubKey (LPCWSTR optional), pszValue (LPCWSTR optional), dwType (DWORD), pvData (void* optional), cbData (DWORD)
r1, _, err := procSHSetValueW.Call(
	uintptr(hkey),
	uintptr(unsafe.Pointer(windows.StringToUTF16Ptr(pszSubKey))),
	uintptr(unsafe.Pointer(windows.StringToUTF16Ptr(pszValue))),
	uintptr(dwType),
	uintptr(pvData),
	uintptr(cbData),
)
_ = err  // syscall.Errno (valid when the call sets last-error)
_ = r1   // INT

function SHSetValueW(
  hkey: THandle;   // HKEY
  pszSubKey: PWideChar;   // LPCWSTR optional
  pszValue: PWideChar;   // LPCWSTR optional
  dwType: DWORD;   // DWORD
  pvData: Pointer;   // void* optional
  cbData: DWORD   // DWORD
): Integer; stdcall;
  external 'SHLWAPI.dll' name 'SHSetValueW';

result := DllCall("SHLWAPI\SHSetValueW"
    , "Ptr", hkey   ; HKEY
    , "WStr", pszSubKey   ; LPCWSTR optional
    , "WStr", pszValue   ; LPCWSTR optional
    , "UInt", dwType   ; DWORD
    , "Ptr", pvData   ; void* optional
    , "UInt", cbData   ; DWORD
    , "Int")   ; return: INT

●SHSetValueW(hkey, pszSubKey, pszValue, dwType, pvData, cbData) = DLL("SHLWAPI.dll", "int SHSetValueW(void*, char*, char*, dword, void*, dword)")
# 呼び出し: SHSetValueW(hkey, pszSubKey, pszValue, dwType, pvData, cbData)
# hkey : HKEY -> "void*"
# pszSubKey : LPCWSTR optional -> "char*"
# pszValue : LPCWSTR optional -> "char*"
# dwType : DWORD -> "dword"
# pvData : void* optional -> "void*"
# cbData : 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。