You need to find out what options your proxy supports.
If your proxy can not read the inserted Client-IP in the TCP-Options, then you need to use another way.
If your proxy supports reading the X-Forwarded-For HTTP header, you need to make sure the AX1030 inserts it.
Normally you would set you Virtual Service to use HTTP/HTTPS and inserting the headers is very easily done in the HTTP Template.
If for some reason you can not use HTTP, you could look at using aFlex to insert the header in the raw TCP data stream.
Is there a particular reason why you are using TCP-Proxy and not HTTP?