Vba code to edit data that changes with a list box

HI

I am looking for VBA Code to erase specific data that is copied to a sheet when a drop box item is chosen. How can i code it that if that list item is changed it must go and find the data that was copied on that sheet that and delete it.

The Sheet SO has the drop box and then copies to the Q sheet from a worksheet that has the same code

Many thanks

In advance