In a control's MouseDown event handler, save the mouse position. In the MouseMove event handler, move the control by the distance the mouse has moved.

Private Sub Command1_MouseDown(Button As Integer, Shift As _
    Integer, X As Single, Y As Single)
    xDown = X
    yDown = Y
End Sub

Private Sub Command1_MouseMove(Button As Integer, Shift As _
    Integer, X As Single, Y As Single)
    If Button <> vbRightButton Then Exit Sub

    MoveCtl Command1, X, Y
End Sub

Private Sub MoveCtl(ctl As Object, X As Single, Y As Single)
Dim newLeft As Single
Dim newTop As Single

    newLeft = ctl.Left + X - xDown
    newTop = ctl.Top + Y - yDown
    ctl.Move newLeft, newTop
End Sub