Access to DOORS computed Attribute via OSLC

I am developing an application to import and export requirements from and to DOORS via OSLC.

On import, I get all the real attributes of the requirement as specified by the Instance Shape.  My specific case is with respect to Object Number. When I perform a Get Resource for a requirement, I see the "object number" property but it never has a value.   I am totally new to DXL but thought I would try a simple script to create an attribute for object number with a DXL script.  The documentation seems to indicate that a DXL script is only executed when a view is rendered but given that I am making a call via OSLC and no view is rendered I can understand why no "object number" value in my query result.

So my question is what is the mechanism for getting the value of computed attributes via OSLC?

Thanks a million

James