Oh what have I missed?

>>>> Window <<<<
Title:
Class: WindowsForms10.window.808.app.0.29e8405
Position: 119, 44
Size: 195, 308
Style: 0x96000000
ExStyle: 0x00010008
Handle: 0x0000000000160564


$sHandle = WinGetHandle("[REGEXPCLASS:WindowsForms10\.Window\.808\.app\.0\.]", "");

i seem to be missing something in my regular expression as it always returns a ''
Hints?