How to exchange data between ABAP and external program

Hi all,

I want to call an external program out of an ABAP program. I want to pass an internal table or a string (ABAP type STRING) to the external program and I want to get back an internal table or a string that the external program has modified or converted.

I don't know at the moment what kind of external program it is, not to mention in which programming language it is written. I hope this doesn't matter.

What solutions are there? It should be a very flexible solution (i.e. platform independant)?

Regards

Frank