[imp] Expand more than name field?

[Chris Shaffer]

I've added a field named lastname to turba, and it is searchable.  
Everything works fine in turba.  However, when using imp to compose a 
message, I can't figure out how to get the "Expand Names" function to 
search both the name and lastname fields.  For example, I have a record 
Davy Jones.  If I put "Davy" in the To: box, it expands correctly to Davy 
Jones.  If I put "Jones" in the To: box, it expands to "Please resolve 
ambiguous or invalid addresses." 
 
Any suggestions welcome. 
 
--  
Chris Shaffer 
cat-imp @ gesserit.net