If you are talking about in a Free Hosting account here, then cURL is already enabled -- but some parts of it are disabled (if I recall, following redirects is disabled --you have to code that manually). The disabled parts are disabled, period. No individual exceptions.
On Free Hosting accounts, you do not have access to php.ini. Period.
All aspects of cURL (including following redirects) should be fully functional on Free Hosting. Do note, however, that Free Hosting greatly restricts which ports you are allowed to actually connect to. If your target is not using HTTP or HTTPS (ports 80 and 443), you may find yourself unable to connect.