DhcpModifyClass

// DHCPSAPI.dll
#include <windows.h>

DWORD DhcpModifyClass(
    LPWSTR ServerIpAddress,   // optional
    DWORD ReservedMustBeZero,
    DHCP_CLASS_INFO* ClassInfo
);

<DllImport("DHCPSAPI.dll", ExactSpelling:=True)>
Public Shared Function DhcpModifyClass(
    <MarshalAs(UnmanagedType.LPWStr)> ServerIpAddress As String,   ' LPWSTR optional
    ReservedMustBeZero As UInteger,   ' DWORD
    ClassInfo As IntPtr   ' DHCP_CLASS_INFO* in/out
) As UInteger
End Function

' ServerIpAddress : LPWSTR optional
' ReservedMustBeZero : DWORD
' ClassInfo : DHCP_CLASS_INFO* in/out
Declare PtrSafe Function DhcpModifyClass Lib "dhcpsapi" ( _
    ByVal ServerIpAddress As LongPtr, _
    ByVal ReservedMustBeZero As Long, _
    ByVal ClassInfo As LongPtr) As Long
' VBA7前提(PtrSafe)。32bit Office では LongPtr→Long。Integer=16bit / Long=32bit / LongLong=64bit。

import ctypes
from ctypes import wintypes

DhcpModifyClass = ctypes.windll.dhcpsapi.DhcpModifyClass
DhcpModifyClass.restype = wintypes.DWORD
DhcpModifyClass.argtypes = [
    wintypes.LPCWSTR,  # ServerIpAddress : LPWSTR optional
    wintypes.DWORD,  # ReservedMustBeZero : DWORD
    ctypes.c_void_p,  # ClassInfo : DHCP_CLASS_INFO* in/out
]

require 'fiddle'
require 'fiddle/import'

lib = Fiddle.dlopen('DHCPSAPI.dll')
DhcpModifyClass = Fiddle::Function.new(
  lib['DhcpModifyClass'],
  [
    Fiddle::TYPE_VOIDP,  # ServerIpAddress : LPWSTR optional
    -Fiddle::TYPE_INT,  # ReservedMustBeZero : DWORD
    Fiddle::TYPE_VOIDP,  # ClassInfo : DHCP_CLASS_INFO* in/out
  ],
  -Fiddle::TYPE_INT)

#[link(name = "dhcpsapi")]
extern "system" {
    fn DhcpModifyClass(
        ServerIpAddress: *mut u16,  // LPWSTR optional
        ReservedMustBeZero: u32,  // DWORD
        ClassInfo: *mut DHCP_CLASS_INFO  // DHCP_CLASS_INFO* in/out
    ) -> u32;
}
// crates: windows-sys provides ready-made bindings for this API.

$sig = @"
[DllImport("DHCPSAPI.dll")]
public static extern uint DhcpModifyClass([MarshalAs(UnmanagedType.LPWStr)] string ServerIpAddress, uint ReservedMustBeZero, IntPtr ClassInfo);
"@
$api = Add-Type -MemberDefinition $sig -Name 'DHCPSAPI_DhcpModifyClass' -Namespace Win32 -PassThru
# $api::DhcpModifyClass(ServerIpAddress, ReservedMustBeZero, ClassInfo)

#uselib "DHCPSAPI.dll"
#func global DhcpModifyClass "DhcpModifyClass" sptr, sptr, sptr
; DhcpModifyClass ServerIpAddress, ReservedMustBeZero, varptr(ClassInfo)   ; 戻り値は stat
; ServerIpAddress : LPWSTR optional -> "sptr"
; ReservedMustBeZero : DWORD -> "sptr"
; ClassInfo : DHCP_CLASS_INFO* in/out -> "sptr"
; ※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 "DHCPSAPI.dll"
#cfunc global DhcpModifyClass "DhcpModifyClass" wstr, int, var
; res = DhcpModifyClass(ServerIpAddress, ReservedMustBeZero, ClassInfo)
; ServerIpAddress : LPWSTR optional -> "wstr"
; ReservedMustBeZero : DWORD -> "int"
; ClassInfo : DHCP_CLASS_INFO* in/out -> "var"
; ※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。

; DWORD DhcpModifyClass(LPWSTR ServerIpAddress, DWORD ReservedMustBeZero, DHCP_CLASS_INFO* ClassInfo)
#uselib "DHCPSAPI.dll"
#cfunc global DhcpModifyClass "DhcpModifyClass" wstr, int, var
; res = DhcpModifyClass(ServerIpAddress, ReservedMustBeZero, ClassInfo)
; ServerIpAddress : LPWSTR optional -> "wstr"
; ReservedMustBeZero : DWORD -> "int"
; ClassInfo : DHCP_CLASS_INFO* in/out -> "var"
; ※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 (
	dhcpsapi = windows.NewLazySystemDLL("DHCPSAPI.dll")
	procDhcpModifyClass = dhcpsapi.NewProc("DhcpModifyClass")
)

// ServerIpAddress (LPWSTR optional), ReservedMustBeZero (DWORD), ClassInfo (DHCP_CLASS_INFO* in/out)
r1, _, err := procDhcpModifyClass.Call(
	uintptr(unsafe.Pointer(windows.StringToUTF16Ptr(ServerIpAddress))),
	uintptr(ReservedMustBeZero),
	uintptr(ClassInfo),
)
_ = err  // syscall.Errno (valid when the call sets last-error)
_ = r1   // DWORD

function DhcpModifyClass(
  ServerIpAddress: PWideChar;   // LPWSTR optional
  ReservedMustBeZero: DWORD;   // DWORD
  ClassInfo: Pointer   // DHCP_CLASS_INFO* in/out
): DWORD; stdcall;
  external 'DHCPSAPI.dll' name 'DhcpModifyClass';

result := DllCall("DHCPSAPI\DhcpModifyClass"
    , "WStr", ServerIpAddress   ; LPWSTR optional
    , "UInt", ReservedMustBeZero   ; DWORD
    , "Ptr", ClassInfo   ; DHCP_CLASS_INFO* in/out
    , "UInt")   ; return: DWORD

●DhcpModifyClass(ServerIpAddress, ReservedMustBeZero, ClassInfo) = DLL("DHCPSAPI.dll", "dword DhcpModifyClass(char*, dword, void*)")
# 呼び出し: DhcpModifyClass(ServerIpAddress, ReservedMustBeZero, ClassInfo)
# ServerIpAddress : LPWSTR optional -> "char*"
# ReservedMustBeZero : DWORD -> "dword"
# ClassInfo : DHCP_CLASS_INFO* in/out -> "void*"
# 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)。