[samolalex]

В общем-то вот, что получилось:

server static void getLanguage()
{
    dll dll = new dll("user32");
    dllFunction GetKeyboardLayout = new dllFunction(dll, "GetKeyboardLayout");
    #define.RU("68748313")
    #define.EN("67699721")
    ;

    GetKeyboardLayout.arg(ExtTypes::DWORD);
    GetKeyboardLayout.returns(ExtTypes::DWORD);

    if(value2string(GetKeyboardLayout.call(0)) == #RU)
    {
        info("RU");
    }
    else
    {
        info("EN");
    }
}