I just got this remote today (because both my dvd player and tv remote were becoming useless). I got it all set up and almost all the buttons work (menu, info guide, swap, and pip do not), but I can't seem to find the button to turn the closed captioning option off. This function was turned on by the original remote, which still works to turn it off and on.

Is there a way to program another button on the remote, like the ones listed to do the cc function?

My tv is a Magnavox and the remote is RCRN03BR.

First, just so you know, this forum is intended for users of remote controls made the URC company.  Your remote is made by Universal Electronics, but isn't one of the type that can program individual buttons.  So a better place to have posted would have been General Consumer Remotes.  But now that you're here, I'll try to answer.

The RCRN03BR is neither programmable at the individual button level nor is it a "learning" remote.  If it were a learning remote, you'd be able to use your original remote to teach the CC signal to the learning remote.

Either you need to accept the level of capability you've already got, or you need to get a learning remote.  I prefer the RCA RCRP05B, which both can learn signals and also be manually programmed for many individual functions, which is useful when the original remote is missing or broken.

The URC W7 or the Sony RM-VLZ620 are also very capable learning remotes.