Call an ABAP program or a function module from command prompt/python script

Question

Dear All,
I want to call a function module/ABAP program from command prompt or a python script.
Let me explain with an example.
There is a function module "z_add" that takes  two integers as input parameters and generates their sum.
the sum is the output parameter.
Now i want to call this function module from command prompt / python script and pass parameters to this function module.
In return i must get the sum(i.e. the output of function module).
I tried using STARTRFC ,was able to call the FM but could not get the return value(output) from FM.
Can you please provide me the code of such a function module and the method to call it thereby passing parameters and getting the sum.
Thanks and regards,
Gaurav
Edited by: gauravkec2005 on Mar 4, 2010 7:41 AM

Answer 1

thank you both!  helpful answers! :o)
anyway! 
i have written the program which is called from the SAPScript:
    /:       PERFORM GET_VATNUMBER IN PROGRAM ZFI_F140_OPERATIONS
    /:       USING &BKPF-BUKRS&
    /:       CHANGING &VATNUMBER&
    CE       VAT Registration No : &VATNUMBER&
    REPORT zfi_f140_operations.
    FORM get_vatnumber TABLES in_par  STRUCTURE itcsy
                              out_par STRUCTURE itcsy.
      DATA: lv_co_code TYPE bukrs,
            lv_vat_no  TYPE stceg.
      READ TABLE in_par WITH KEY name = 'BKPF-BUKRS'.
      MOVE in_par-value TO lv_co_code.
      SELECT SINGLE stceg FROM t001
        INTO lv_vat_no WHERE bukrs = lv_co_code.
      out_par-name = 'VATNUMBER'.
      WRITE lv_vat_no TO out_par-value.
      CONDENSE out_par-value.
      MODIFY out_par INDEX 1.
    ENDFORM.              
it is not working and i cannot work out why... 
i have not been ABAPing for very long but have had a go.... 
any thoughts as to what i have done wrong?
or point me where i should be looking?  thank you!