shell vs shelldef

I can't shell this particular program but I can shelldef it...has to do with WS extension I assume.
No matter....if I shell I can get the hwnd easily...
How do I get the hwnd of the program when I have to use shelldef instead of shell.

Ie.
s390.Ws is the app name..it won't shell but I can open it using shelldef which opens with app extension.

I need the hwnd of the s390 so I can sendkeys to it.

Thanks,
Wayne