I have done this in the past. My borderless window requires a region control.
Before Global Includes:
HWND EQUATE(UNSIGNED)
Inside Global Map
MODULE('Windows API')
SendMessage(HWND,UNSIGNED,UNSIGNED,UNSIGNED),LONG,PASCAL,NAME('SendMessageA')
ReleaseCapture(),BOOL,PASCAL
END
On the Region control.Accepted:
ReleaseCapture()
lngReturnValue# = SendMessage(0{PROP:HANDLE},161,2,0) //Please equate these values
Cheers