I got it fixed now. I did replace the "0000" with "\S0000"
this is how the code is now
Private Sub UserForm_Initialize()
  With Worksheets("CustomerList").Range("F7")
    .Value = .Value + 1
    Me.txtStaffID = Format(.Value, "\S0000")
  End With
End Sub
Anyways, Thanks for the help.
I do appreciate that.