Reference Variable to drive the POV on a Management Report

Summary:

Can a Reference Variable be used as a Variable to drive the POV on a Management Report?

Content (required):

I would like to have a repository of Variables that can be changed in a Reference Doclet at the start of the Authoring phase to drive embedded content from Management Reports.

I have created an Excel Reference Doclet with the Reference Variables but when I add the Reference variable to the subsequent Reference Doclets (Management Reports) as part of the Point of View I get and error saying that #missing is not defined.