General :: Getting Extended Ascii (chars > 127) To Work

I have an application where the client is written in Visual Studio (C#), run on PCs, and the server end has traditionally been SCO. We're now migrating to Linux. I can, for example, input "Test This" in a text box on the client, and when the server end is SCO, it is able to 'accept' the character sent to it from the client. When I try this same example on Linux, that character (hex D1) does not 'make it' from the client to the server.

The problem is not on the client, and I have verified that the telnet connection is in fact passing these extended characters, but they are not recognized properly by the Linux server.In researching this, I've played with setting the LANG environmental variable from LANG=en_US.UTF-8 to several of the other possible values found in /usr/lib/locale, for a european locale (the end user is actually in Spain), and these 'euro' characters are still not handled properly in my application.Would anyone be able to point me to any specific env variable settings, and/or anything else that would resolve this issue?