Calling Business Functions outside of JDE OneWorld Xe environment

Some of you may be familiar with teh CL command "RUNUBE", which allows you to call a One World UBE outside OneWorld in a CL...Has anyone tried calling business funcitons outside of JDE? The approach that comes to mind is writing a RPG "wrapper" program that makes API calls? VERY unfamiliar with this kind of programming and could certainly use some direction..
Thanks
TOm