Belong here ??

Or perhaps in the newbie section, but it is advanced to me....

I sat at home last night trying to...hm, lets put it this way:
I've done 8 selections on a layer and erased the black color inside those selections on the layer beneith. OK now I got something looking like a window. This is no real effort to get a good pic, just out to get the posibility of makin an effect.

The effect I'm strivin to get is light shining through a window on to the black (or whatever) inside the window. Can anyone help, doesn't seem to get it to work an' I can't find any help out there, So I figured, if it's possible I'll get help in TPS.

..or is it not possible to do in PS ? I know it can be done in 3D proggys, but I would like it done in PS...