How to skin other windows?

[Fox]

I tried to make a simple program to skin any window.. I used this code:

    Dim DC As Long
    Dim hWnd As Long
    Dim Temp As Rect
    
    hWnd = Window(SelectedWindow).hWnd
    
    'Get rect
    GetClientRect hWnd, Temp
    DC = GetWindowDC(hWnd)

    'Setup rect
    Temp.Left = Temp.Left + 4
    Temp.Top = Temp.Top + 4

    Temp.Right = Temp.Right - Temp.Left + 4
    Temp.Bottom = Temp.Bottom - Temp.Top + 4

    'Copy picture
    With Temp: BitBlt DC, .Left, .Top, .Right, .Bottom, Front.hDC, 0, 0, vbSrcCopy: End With

The code actually works, see the screenshot:


However, can you help me with this?

• How can I get the offset (4 in the example) from windows?
• Any way to only paint into the BG of the window? (not over controls)
• How to keep the picture there? (enabled "AutoRedraw" for that window)

Thanks for ideas!