File->Xi->File & RFC scenario

Hi guys,

I have a scenario where file is picked up from one file system(A) and is put in

file system(B) .

Now there is R/3 system which will pick up the files from file system(B)

by a already developed abap program.

But the problem is R3 doesnot want ot poll the File system (B) every 10 min

to see the file has arrived or not. it needs a trigger in form of RFC from XI

After R3 gets a trigger , it will pick up the file from file system(B).

How can we do this using BPM

Regards