Can anyone give a similar snippet :Reading from spool

I have spool with me of MB51 output created programmatically and i want it back in an internal table.I use this code

I have written the code but i have some doubts.

Firstly i dont know the exact structure which i must assign to output internal table.

Secondly i get an error like UC_OBJECTS_NOT_CHAR

call function 'RSPO_RETURN_ABAP_SPOOLJOB'

exporting

rqident = SPOOL_NUMBER

tables

buffer = itab

exceptions

no_such_job = 1

not_abap_list = 2

job_contains_no_data = 3

selection_empty = 4

no_permission = 5

can_not_access = 6

read_error = 7

others = 8.