URGENT : RFC from SAP

Hi Experts,

I have a VB Application(EXE) which gives me a price value.

Now i need to call that EXE and import the value and use it in my SAP-Report

1) How do i call the VB EXE and get the value. Can we do that using RFC .

2) Where should i store that EXE: Application Server or Presentation Server ?

Can any one provide me with the detailed procedure and Examples

I promise to reward points !!!

Thanks in Advance

AK