if you want to click a button you can just do:
Code:
' on Form1
Private Sub Command1_Click()
    Form2.Command1.Value = True
End Sub
however, I would recommend doing something like:
Code:
' On Form1
Private Sub Command1_Click()
    Form2.ClickButton
End Sub

' On Form2
Public Sub ClickButton()
    Call DoSomething
End Sub

Private Sub Command1_Click()
    Call DoSomething
End Sub

Private Sub DoSomething()
    MsgBox "Clicked"
End Sub