Accessing Xcode resources

This is my first time doing Mac development. I'm porting a game from Windows to Mac OS X. The game was written using C++ and SDL. It has a data directory with images and fonts and such. I'm using Xcode and I put all the images into the Xcode Resource section.

The program compiles fine but when I run it, it immediately exits because it can't find any image files. How do I access the resource section?

My command is: surfacepointer = SDL_LoadBMP("data/file.bmp");
I've tried removing the data directory reference and using all sorts of different paths but nothing seems to work.

Any suggestions?

Thanks in advance