Delete records in update routine

Hi Everyone,

I have a keyfigure called " <b>Quantity</b> " and I would like to not update the quantity if my Characteristic CS_ITEM has a value "HEADCO" and Characteristic CURTYPE has a value "10". Can you please suggest some abap code in either update rule or start routine to skip or not update records if these values are present mentioned above.

Thanks

Asad