[HR-PY] Querying PNP LDB infotype - wise

Hello !

I got a question about optimizing data fetching from LDB.

Nowdays i do something like :

INFOTYPES: 0657.

GET pernr.
LOOP AT P0657 WHERE somefield IN criteria.
"do stuff here
ENDLOOP.

Problem with this approach is Preformance - i only want to process records that have IT0657 entry - but since no select options are given on screen GET pernr fetches every personal number - is there any way to restrict that ?

i know i could do SELECT to db and then insert its results as LDB params to loop only on the relevant records - problem with that is that my Selection Options regarding PERNR in LDB get lost that way - is there something more accurate ?