How to force leading zero in a format for a form's caption

[Pookiemeister]

When my userform initializes, I am using the following format in the form's caption P4-2021-##. This starts in range "A6". However, when this form is first created Range("A6") is empty and therefore should start with "P4-2021-01". When a value is entered in Range("A7") the ## should increment by one, so it would be "P4-2021-02" and so on. How can I have the code look at the last two numbers of the previous cell and add one to the last two digits using vba. Like this, but this is wrong.

Private Sub UserForm_Initialize()
   
    Dim Numbers As String
   
    Numbers = "01"
    MsgBox CLng(Format(Numbers, "##"))
     
    Me.Caption = ("P4" & "-" & Format(Now(), "yyyy")) & "-" & Format(Numbers, "##")
End Sub

How do I force a leading zero until the number reaches 10?

Thank you

 

[shg]

I can't tell what you're trying to do, but maybe this will help:

Sub Init()
  Dim i As Long
  
  i = 100 * Year(Now())
  Debug.Print NextCaption(i)
  Debug.Print NextCaption(i)
  Debug.Print NextCaption(i)
End Sub

Function NextCaption(ByRef i As Long) As String
  i = i + 1
  NextCaption = Format(i, "P4-0000-00")
End Function