Change button caption on right click

Can you code events behind a right click? For instance, I want to make the caption of a button an "X" on left click and an "O" on right click. Is this possible?

try this

VB Code:

Private Sub Command1_MouseDown(Button As Integer, Shift As Integer, X As Single, Y As Single)
If Button = vbLeftButton Then Command1.Caption = "X"
If Button = vbRightButton Then Command1.Caption = "O"
End Sub