How do I create an object instance from a tag?

["Steve" <nospam_steved94@attbi.com>]

I would like to create a function that returns a reference to a class wide
object based on the external name.  Something along the lines of:

function Create_Object( external_name : String ) return objAcc is
  returnTag : Ada.Tags.Tag;
begin
  returnTag := Ada.Tags.Internal_Tag( external_name );
  return ??? some function of returnTag ???
end Create_Object;

Can this be done?

I've perused the rationale and the RM and haven't run across anything.

Steve
(The Duck)