Try:
{If{REF Dropdown2}= "Donald Duck" "Donald.Duck{If{REF Dropdown1}= "Company B" "@companyb.com"}"}{If{REF Dropdown2}= "Mickey Mouse" {If{REF Dropdown1}= "Company B" "Mickey_Mouse@companyb.com" "Mickey.Mouse"}}{If{REF Dropdown2}= "Minnie Mouse" {If{REF Dropdown1}= "Company B" "Minnie_Mouse@companyb.com" "Minnie.Mouse"}}{If{REF Dropdown1}= "Company A" "@companya.ca" {If{REF Dropdown1}= "Company C" "@companyc.ca"}}

Note: This has nothing to do with macros - it concerns only field coding.

__________________
Cheers,
Paul Edstein
[Fmr MS MVP - Word]