Currently I use the following code to populate a cell on my worksheet from a
TextBox on a DialogBox:

Private Sub CommandButton1_Click()

Dim rng
Set rng = Cells(ActiveCell.Row, 1)
rng(1, 1).Value = TextBox3.Text

End Sub

Also on that DialogBox is a CheckBox. What I would like to have happen is,
if the CheckBox is selected (checked) then an X would be placed in cell 3 of
the current row "rng(1, 3)".