Can I get a description field to link to a custom propertyafter linking it to a model or assembly property?

I created several sheet formats. I have all of the descriptionfields linked to the individual assembly or model description thatcomes in. Some times we have cases that we need to be able to writein our own description when it is an upper level assembly thatinvolves several sub assemblies.

Can I link the sheet to both? I want a default to be the assembly/part, but I want to be able to override it with a description froma sheet property if needed.

Can I do this or do I need another sheet?
SolidworksDrawings And Detailing