This procedure applies to T3C since version 12.
If you have an older version, update T3C first, then follow this procedure.
proxy = 1 proxy.server = address:port proxy.user = user proxy.password = password
For older versions of T3C, use the following procedure.
service.proxy = 1 service.proxyServer = address:port service.proxyUser = user service.proxyPassword = password