Hi,
If cdhdr is known then use objectid .
DATA: it_cdhdr TYPE TABLE OF cdhdr .
SELECT * INTO TABLE it_cdhdr
FROM cdhdr
WHERE
objectclas IN s_class AND
udate IN s_udate AND
tcode IN s_tcode .
CHECK it_cdhdr IS NOT INITIAL .
DATA: it_cdpos TYPE TABLE OF cdpos .
SELECT * INTO TABLE it_cdpos
FROM cdpos
FOR ALL ENTRIES IN it_cdhdr
WHERE
objectclas EQ it_cdhdr-objectclas AND
objectid EQ it_cdhdr-objectid AND
changenr EQ it_cdhdr-changenr AND
tabname IN s_tabnm AND
chngind IN s_chngi .
regards.