Hi,
I was trying to do the same thing! So I purchased this machine:
LNS Technologies High Tech Products for Hobby, Edcucation and Business
And a friend with a CNC machine made me an aluminum mold for a guitar pick.
I tried various plastic materials and eventually had success with Acetal (Delrin™)
Attached are photos of some of my experiments molding plastic parts with that machine.
Hope this helps.