same case value but run different formula if first character is

I am making a renaming script and all is working unless I have a specific file name. Which is common in every project.

I am renaming file names based on the file length. I have 2 file lengths that are both = to 12 but need to be named differently. Can I have an if statement inside of that one case to see if the first Character is =0,c,e"?

Sub Convert()
Application.ScreenUpdating = False

Dim rng As Range, aCell As Range
Dim val As String
Dim LastRow As Long
LastRow = Range("A" & Rows.Count).End(xlUp).Row
Set rng = Range("A2:A" & LastRow)

For Each aCell In rng.Cells
Select Case Len(aCell)
    Case 12
        If val = Left(aCell, 1) = "0" Or "c" Or "e" Then 'Example: 01730101.pdf = S-173-0101.pdf
        val = "S-" & Mid(aCell, 2, Len(aCell) - 9) & "-" & Mid(aCell, 5, Len(aCell) - 8)
        Else 'Example: 173d0071.pdf = S-173-D7.pdf
        val = "S-" & Left(aCell, Len(aCell) - 9) & "-" & Mid(aCell, 4, Len(aCell) - 8)
        End If
    Case 13 'Example: 173d00710.pdf = S-173-D7.pdf
        val = "S-" & Left(aCell, Len(aCell) - 10) & "-" & Mid(aCell, 4, Len(aCell) - 9)
    Case 15 'Example: 173d170c071.pdf = SD-170-C7.pdf
        val = "SD-" & Left(aCell, Len(aCell) - 15) & Mid(aCell, 5, Len(aCell) - 12) & "-" & Mid(aCell, 8, Len(aCell) - 12)
    Case 16 'Example: REF-173d0071.pdf = REF-173-D7.pdf
        val = Left(aCell, Len(aCell) - 9) & "-" & (Mid(aCell, 8, Len(aCell) - 12))
    Case 17 'Example: REF173d00710.pdf = REF-173-D7.pdf
        val = Left(aCell, Len(aCell) - 10) & "-" & (Mid(aCell, 8, Len(aCell) - 13))
On Error GoTo whoa
    Case Else
        val = "_Mod " & Left(aCell, Len(aCell) - 4)
End Select

val = UCase(val)

val = val & " " & aCell.Offset(, 2) & aCell.Offset(, 3)

aCell.Offset(, 1).Value = val
Next
Call RemoveZero
Call RemoveBadChar
    Range("C1").Select
    Worksheets("Rename").Columns("B").AutoFit
    Application.ScreenUpdating = True
whoa:
MsgBox "Please delete any empty rows."
ActiveSheet.Range("A1").End(xlDown).Offset(1).EntireRow.Select
Application.ScreenUpdating = True
Exit Sub
End Sub

Thx for any help