resetting xemacs' idea of home directory

[Tim Connors]

I want to reset a running xemacs' idea of where my $HOME directory is (I 
want to temporarily work in a different filesystem with my main xemacs 
process) so that when I open a file in ~/thesis/..., it goes to 
<directory>/thesis/....

(setenv "HOME" ...) didn't do what I was hoping it would do (obviously it 
would for subshells).  Is there a way?

-- 
Tim Connors