Hi
It is possible if your position names are unique. In one of my implementation their positions names were like ER0001 , ER0002 .... So we were able to do so.
Let me know if you have unique position text. If it is correct, ask ABAPer to find posiotion object id based on position text. The information will be available in table HRP1000 table. This code can be written in LSMW or BDC of master data upload program.
It all depends on scenario and available informations.
Regards
Ajay