Hola ENTER, va queriendo, hay muchas formas que se me ocurren pero bueno, dale como lo estas haciendo, por lo que preguntas agregas estas dos lineas
UserControl.Line (0, 0)-(23, UserControl.ScaleHeight), RGB(238, 238, 238), BF
UserControl.Line (23, 0)-(23, UserControl.ScaleHeight), RGB(194, 193, 193)
Private Sub DrawButton()
Dim PT As POINTAPI, Pen As Long, hPen As Long
Dim i As Long, ColorR As Long, ColorG As Long, ColorB As Long
Dim hBrush As Long
UserControl.Cls
With UserControl
UserControl.Line (0, 0)-(23, UserControl.ScaleHeight), RGB(238, 238, 238), BF
UserControl.Line (23, 0)-(23, UserControl.ScaleHeight), RGB(194, 193, 193)
'hBrush = CreateSolidBrush(RGB(0, 60, 116))
hBrush = CreateSolidBrush(RGB(194, 193, 193))
FrameRect UserControl.hdc, rc, hBrush
DeleteObject hBrush
'Left top corner
SetPixel .hdc, l, t + 1, RGB(205, 207, 209)
SetPixel .hdc, l + 1, t + 1, RGB(232, 232, 234)
SetPixel .hdc, l + 1, t, RGB(205, 207, 209)
'right top corner
SetPixel .hdc, r - 1, t, RGB(205, 207, 209)
SetPixel .hdc, r - 1, t + 1, RGB(232, 232, 234)
SetPixel .hdc, r, t + 1, RGB(205, 207, 209)
'left bottom corner
SetPixel .hdc, l, B - 2, RGB(205, 207, 209)
SetPixel .hdc, l + 1, B - 2, RGB(232, 232, 234)
SetPixel .hdc, l + 1, B - 1, RGB(205, 207, 209)
'right bottom corner
SetPixel .hdc, r, B - 2, RGB(205, 207, 209)
SetPixel .hdc, r - 1, B - 2, RGB(232, 232, 234)
SetPixel .hdc, r - 1, B - 1, RGB(205, 207, 209)
End With
DeleteObject regMain
regMain = CreateRectRgn(0, 0, w, h)
rgn1 = CreateRectRgn(0, 0, 1, 1) 'Left top coner
CombineRgn regMain, regMain, rgn1, RGN_DIFF
DeleteObject rgn1
rgn1 = CreateRectRgn(0, h - 1, 1, h) 'Left bottom corner
CombineRgn regMain, regMain, rgn1, RGN_DIFF
DeleteObject rgn1
rgn1 = CreateRectRgn(w - 1, 0, w, 1) 'Right top corner
CombineRgn regMain, regMain, rgn1, RGN_DIFF
DeleteObject rgn1
rgn1 = CreateRectRgn(w - 1, h - 1, w, h) 'Right bottom corner
CombineRgn regMain, regMain, rgn1, RGN_DIFF
DeleteObject rgn1
SetWindowRgn UserControl.hwnd, regMain, True
End Sub
Saludos.