Submit 'RKAEP000' WITH SCRNAME

Hi Experts,

I call the program of transaction 'KSB1' with program name RKAEP000.

I need the field CPUDT, so my idea was to create a custom selection screen and submit the program with the selection screen.

In ksb1 with my selection screen the field for the CPUDT was SO_C03 so I came up with this solution:

SUBMIT 'RKAEP000'       WITH p_kokrs EQ p_kokrs
                        WITH p_tcode EQ p_tcode
                        WITH kostl IN s_kostl
                        WITH kstar IN s_kstar
                        WITH SO_C03 IN s_cpudt
                        WITH p_disvar EQ p_layout
                        WITH R_BUDAT in s_budat
                        WITH SCRNAME EQ 'TESTSSCREEN'
                        USING SELECTION-SCREEN 100
                        EXPORTING LIST
                        TO MEMORY AND RETURN.

Unfortunately the selection of CPUDT doesnt work. Am I missing something or doesnt it work this way?

Help is appreciated.

Regards