SAP PM: How to modify data in the AFFH table?

Hi friends,

I have the key fields AUFPL and PZLFH for the table AFFH.

I need to implement the next logic to my report.

If there already exists a row with the same key fields then Update the row, else Insert a new row with these key fields.

I can't do it directly, so I want to know is there any standard FM/Method/BAPI that I can use for that?

Thanks.