Hi Daniel, I think you might need to disclose a little more information before anyone can help. What does your skin cream incorporate already? What aspect of the bamboo would you be looking to use in it?
The soap should be easy - either you can look to use a melt-and-pour soap and add your charcoal as a simple means of approach. Otherwise you could simply do cold or hot-process soaps and add the charcoal therein. It shouldn’t really make much of a difference but I’d be inclined to add the charcoal after initial saponification.
There should be formulations/recipes on charcoal soaps already available on the internet - just sub out regular charcoal with your bamboo charcoal! Be sure that you’ve double-checked your lye concentration(s) too, you don’t want a caustic resulting soap.