trigger or something else?

Hello,

I have a table that has to have several fields with different names, 
but equal content. Sounds stupid, but it is because I have 2 
different programs querying the same table for user information and 
each of them uses differently named fields.

Eg. I have fields passwd and password.
When passwd field changes, password must automatically change 
to be the same as passwd.

I was wondering whether I need a trigger for that, or could I 
somehow manage to specify that in the "create table" stmt.

If I need to do it via trigger, then I apparently need the plpgsql, right?
Could you tell which configure option enables that? --enable-
plpgsql? 

Thanks in advamce for any comments.

Emils