soap and purchased fragrancecologn or lotion

Digging around the web but so far having trouble finding an answer to this question:

Can I add fragrance, in cologne form, to homemade soap? I'm planning to do hot process, having done cold process a few times a few years ago. Wondering if once it's traced it's safe to add a fragrance that way.

Same question about adding a scented lotion as a sort of combo super-fatting & scenting strategy.

I have a tragically discontinued scent (Savannah Gardens from Crabtree & Evelyn) in lotion & perfume forms that i'd really love to get into some soap. Trying to make this last...

Thanks for any help!

cheers,
diana