Creating and Loading DialogBox from DLL
See the question and my original answer on StackOverflowSomething like this:
HMODULE module = LoadLibrary("MyDll.dll");
HRSRC res = FindResource(module, "#1234", RT_DIALOG);
DLGTEMPLATE* pTemplate = (DLGTEMPLATE*)LoadResource(module, res);
DialogBoxIndirect(0, pTemplate, hwnd, dlgproc);