honestly I dont think you would find an App for that scenario, I dont expect anyone to write an App to rip cds when its like... really few people who would get a usb cd reader for RT.
the problema its I dont see an app that would read a cd in WinRT... only explorer, so it would only read a cd with files, not an audio cd.
Now, dont listen to this Daniel Gandolfo... Im sorry to say it like this, but dont do it. you can actually run desktop apps in Surface RT, but you need a weird jailbreak that might work, might not work, might even give blue screen. etc etc. but it has worked for alot of people!
and there is alot of software that has been ported to Windows ARM. if you know about it, you could try to get an open source CD ripper program and port it yourself to ARM. or you can go XDA and see if they can do it... it might work or it might not.
in the list of ported apps, for example there is Coolplayer working on RT, it has a cd reader plugin but dont know if it will work on RT, since I guess it should be ported as well. but you can ask in xda.
it sounds possible to find a way to work that out. but you know, you would need a desktop app ported to ARM, because I dont see how a developer would waste time for a scenario like this when its almost impossible to find people trying to rip cds in a surface rt. (same reason why you havent seen rip cd programs ported to RT, but it might be also because someone hasnt requested it)