Is it possible to map a dependency field from a system required drop down field

Is it possible to map a dependency field from a system required drop down field

I am able to map one custom picklist to another.custom picklist without a problem.

 but say I was to map a dependency to a custom picklist from a system required field, even if it is a drop down, the system required fields do not appear in the option list for a parent field.

Example, in potentials I want to map Stage to a custom picklist called "Status" where in i classify the various stages as open or closed.

Is this possible or is there a workaround?