Permisions on WI creation based on WI attribute value

Hi

Is there a way to configure permissions around WI creation based on the
value of an attribute?
For example, I have a Requirement WI which has a custom attribute called
"Type" that can be one of "Use Case, Test Condition, Feature".
By changing the permissions on the "Create a WI of a specific Type" I
can stop someone from creating "Requirements" of any type but if I want
certain roles to only be able to create "Use Case" Requirements?

I thought I could add a "required properties" precondition, but that
only lets me mandate the existence of a value, not that an attribute has
a specific value.

Any ideas?
Thanks
Freddy