Hi Kabil,
Yes, since the code is written in Initialization event, we can overwrite the same by creating the Variant for the particular screen, Call the Submit report like SUBMIT USING SELECTION-SET like shown below, here I have created the variant 'TEST2'.
Call the selection screen as follows.
SUBMIT J_1HSTCD
VIA SELECTION-SCREEN
EXPORTING LIST TO MEMORY
AND RETURN
USING SELECTION-SET 'TEST2'.
To change the variant value using FM FASU_RS_CHANGE_CREATED_VARIANT. Please find the document below.
Mass Change of Variants - Code Gallery - SCN Wiki
If you found more difficult, you can another method using BDC too and there are more number of implicit enhancements available for the program J_1HSTCD as shown below. write the export statement inside implicit enhancement and get the value in the custom program.
Regards
Rajkumar Narasimman