VS 2010 - Crash Course In UTF Encoding

What is happening is I'm trying to process international characters, but the code is falling through (giving up?) and replacing the field with a blank (well, I guess the screenshot is at the bottom)... The customer recently asked for support for Polish characters, and gave us a list of which ones he wants added.

This is the entire function:

Code:
Protected Function chkExtchars(ByVal name As String) As String
Dim j As Integer = 0
Dim dt As New DataTable
Dim c() As Char = Nothing
Dim n As Integer
Dim nc As Char
Dim newname As String = ""
dt = HttpContext.Current.Session("xChars")

[Code] ....

But maybe it needs to be sequential? (the numbers on the far left?)