You have to use this:
DATA: gv_prctr TYPE cepc-prctr.
SELECT-OPTIONS: so_prctr FOR gv_prctr.
select prctr from cepc into table t_prctr
where prctr in so_prctr.
The data has to be filled like a parameter when you execute the program, but you can inizialice on the INITIALIZATION event like this:
data: gs_so_prctr LIKE LINE OF so_prctr.
gs_so_prctr-option = 'EQ'.
gs_so_prctr-sign = 'I'.
gs_so_prctr-option = your data.
append gs_so_prctr TO so_prctr.
Regards,
Alberto.