I have some caulerpa profilera and dont know how to put it in my tank. Right now the root parts are just shoved in the sand. Is there another way to do this???
You're doing pretty much what you need to do...take your finger and poke the rhizomes into the substrate. If you want it to grow on your rockwork, you can shove it into a crevice and let it attach, or wrap some cotton thread around it to hold it in place. The cotton thread will eventually fall away and the macro will have attached itself to the rockwork.
Another possible way is to use a loose rubberband to aid it staying on the rocks. It usually takes hold in a few days to a week.
I applaud you for using macro!
Reef on!