VBA Question - Password Validation

 

The first uppercase letter is followed by more characters (all uppercase alphabets) and/or digits; however, the number of digits cannot be more than 2. (Note: the number of digits can be zero, but not more than two).

 

I cannot get my head around how to validate that the input contain 2 or less numeric values. Could someone please give me a hand? My code is provided below.

 

Sub Password()

Dim pass1 As String

  Dim pass2 As String

  Dim userinput As String

  Dim isPasswordUnique As Boolean

  Dim passwordCells As Range

  Dim pos28 As Integer

  Dim midChar As String

  Dim isValid As Boolean

  ' Ask for valid password until unique.

  Do

    ' Ask for password until clears validation.

    Do

      isValid = True

      userinput = InputBox("Please enter a password that meets this criteria:" & vbNewLine & vbNewLine & _

      "First character must be a capital letter." & vbNewLine & _

      "Password must be 8 chacters in length." & vbNewLine & _

      "All characters must be capital letters or digits." & vbNewLine & _

      "No more than 2 numeric digits.", "Password" & vbNewLine)

      ' Blank entry check.

      If userinput <> "" Then

        pass1 = userinput

        ' Length check.

        If Len(pass1) <> 8 Then

          isValid = False

        ' First character capital check.

        ElseIf Not (Left(pass1, 1) >= "A" And Left(pass1, 1) <= "Z") Then

          isValid = False

 

        ' Other characters check.

        Else

          For pos28 = 2 To 8

            midChar = Mid(pass1, pos28, 1)

            If Not ((midChar >= "A" And midChar <= "Z") Or _

                (midChar >= "0" And midChar <= "9")) Then

              isValid = False

              Exit For

            End If

          Next

        End If

      End If

      If Not isValid Then

        MsgBox "The password is not valid.", vbInformation, "Invalid"

      End If

    Loop Until userinput <> "" And isValid

    Set passwordCells = ActiveWorkbook.Worksheets("Password").Range("A1")

    ' If password valid check against password list

    isPasswordUnique = True

    Do Until passwordCells = ""

      If pass1 = passwordCells.Value Then

        isPasswordUnique = False

        Exit Do

      End If

      ' Next cell

      Set passwordCells = passwordCells.Offset(1, 0)

    Loop

    If Not isPasswordUnique Then

      MsgBox "The password you entered, " & pass1 & ", is valid, but, " _

        & "already in use. Try another password.", vbInformation, "Password in use."

    Else

      pass2 = InputBox("Please reenter your password for verification.")

      If pass2 <> pass1 Then

        MsgBox "The passwords do not match. Please try again.", vbInformation, "No verification"

      Else

        MsgBox "Congrats! Your new password is " & pass1 & ".", _

          vbInformation, "Password Set"

        ' Add new password to password list.

        ActiveWorkbook.Worksheets("Password").Range("A1").End(xlDown).Offset(1, 0) = pass1

      End If

    End If

  Loop Until isPasswordUnique And pass2 = pass1

 

End Sub