Windows parameter

[shuji]

Can someone help me with this:
I have a library which I try to import from D
//funcs.lib
//windows includes...
HWND hwnd;
int setHWND(HWND extHwnd){
        hwnd = extHwnd;
        return 0;
}

//main.d
pragma(lib, "gdi32.lib");
import core.runtime;
import core.sys.windows.windows;
extern (C++) {
        int setHWND(HWND hwnd);
}
int main(int argc, char **argv) {
//windows initializers
        setHWND(hwnd);
        return 0;
}

but when I try to import that function this comes:
   Error 42: Symbol Undefined ?setHWND@@YAHPAX@Z (int cdecl
setHWND(void *))
--- errorlevel 1

it seems like I cannot use HWND directly.