HOW TO ADD IMPLICIT PROPERTIES TO ITEM SUCH AS WANDS?

I want to test out an enchant sorc build and I wanted to add a wand with +3 to fire skills and +3 to enchant. I can add the +3 fire skill but when I try to add the +3 enchant it does not appear as an option. I tried a bunch of different sorc wands and both magic / rare / white items and it never gives me that option. Is there something I might be doing wrong? Thanks in advance for any pointers!