VAR_OUT inside cursor

Hello,

I need to calculate cumulative stocks. I want to do it using SAP HANA analysis process. I created test procedure with cursor and VAR_OUT  inside cursor. When i call this procedure i always get only one value. How i can get more then one value from this procedure?

DECLARE CURSOR c_cursor1 FOR

Select "SUPNUM" FROM "_SYS_BIC"."Stocks/STOCKS"

                              WHERE "SUPNUM" IN ('00000028345', '00000039053')

GROUP BY "SUPNUM";

FOR cur_row as c_cursor1 DO

     VAR_OUT = Select "SUPNUM" FROM "_SYS_BIC"."Stocks/STOCKS"

                           WHERE "SUPNUM" = cur_row.SUPNUM GROUP BY "SUPNUM";

END FOR