The Objective-C runtime has not been ported to Android yet. It shouldn't be too much work, but still, without a working knowledge of the language I doubt you'll have an easy time porting it.
What you are trying to do is going to be hard for a generic application, but should be possible for games, if you choose to develop the game in plain C (which is supported by both the Android NDK and the iPhone). You'd have to write up some glue code to pass input events from the Obj-C and Java environments into your C code, but that shouldn't be much of a problem - Objective-C allows you to directly call into your C code and there are plenty of example projects which do exactly this for Android.
