Reference Attribute to String

So I am trying to take a reference attribute "Assistant" and convert it to a String to populate msexchAssistantName.

I thought I might be able to do it with an outbound sync rule in the FIM Portal, but I cannot seem to get the custom expression right. "Assistant".Value.ToString

I found alot of String to Reference docs online but not Reference to String.

any help is appreciated.

Thanks

Russ

Russell Lema