This maybe,

If strNewWSName Like "*:*" Or strNewWSName Like "*/*" Or strNewWSName Like "*\*" Or strNewWSName Like "*?*" Or strNewWSName Like "***" Or strNewWSName Like "*]*" Or strNewWSName Like "*[*" Then
                MsgBox Prompt:="Special Characters are not allowed as part of a worksheet name.", _
                Buttons:=vbExclamation, Title:=""
                GoTo ShowInputBoxEnterNewWSName
            End If