>The error message is "OLE error code 0x80040154: Class not registered.
>
>Another interesting point:
>declare integer findwindow in win32api string cnull, string cwinname
>Fails as well

I don't think they're related. API function call registration is case sensitive in terms of the function name. The proper syntax would be:

DECLARE INTEGER FindWindow IN Win32API;
  STRING @cnull, STRING @cwinname