>What if the app is already opened - can I switch focus to the window and make it the foremost window?

If you know the caption of this application, try

DECLARE Long FindWindow IN WIN32API String ClassName, String WindowTitle
*DECLARE Long SendMessage IN WIN32API Long hWnd, Long Msg, Long wParam, Long lParam
 
lcWindowTitle = "RI Settings DM.JPG - Paint" && your caption goes there
 
hWnd = FindWindow( Null, lcWindowTitle )
IF hWnd <> 0
   declare integer SetForegroundWindow in win32api Integer

    SetForegroundWindow(hWnd)
endif