Hello. I'm trying to format the date entry in a textbox on a form so that when a future date is entered via the form onto the relevant cell in the active sheet, it will always show in the following format, '01/mm/yyyy' in the cell. The first day of the month should always be 01 and there should be slashes showing. So no matter how the user enters the date in the textbox (whether they use the '/' or not, and/or put the day other than 01) it will always override with the correct format into the cell. The textbox is always initialized to show '01/mm/yyyy' which the user will type over. I have tried a couple of ways but can't get it to work properly:

This is the line of code I'm working from, where textbox3 is the place the date is entered:

If OptionButton5 Then Cells(Nextrow, 3) = TextBox3.Text

I have tried using:
TextBox3.Text = format(textBox3.Text, "01/mm/yyyy")
which just literally adds 01/mm/yyyy into the box after the textbox text

and I've tried:

With TextBox3
Select Case Len(.Text)
Case 2, 5
.Text = .Text & "/"
End Select

If InStr(.Text, "//") Then
.Text = Replace(.Text, "//", "/")
End If
End With

which doesn't do anything. I have also considered using the calender but this isn't suitable on this occasion. I would appreciate help with this, thanks!