If you are getting all your currency symbols on the Unix side (which I assume you are) then there will be some way to do it.
Firstly, there is (I expect, maybe Robert can confirm) the possibility of having your own specific code-page. I had a similar problem a few years ago, with a Tandem machine using UK ASCII, COMMS gear using European ASCII and Mainframe using American EBCDIC(!).
We had two and theree character alpha codes for currencies, but no-one (before I worked there
) gave any thought to currency symbols in stock names, which were scrambled daily.
Once everything was in line, everything worked. This was DOS/VSE, but I imagine the same priciple.
So, if you can get your own code page (and remember about going back, just so you're ready for files in the other direction) your problems will be over.
So, first step is some research, then a polite request to your systems' guys.
If you can't get anywhere that way, then there will be other ways.
When you do checking of solutions, use a single record file with values from 00 to 7F or FF (depending on the ASCII) so that you can see what will happen to every byte. By all means set up the file and try it with UTF-16.