[wmii] changing font size of terminals

Hi,
I would like to decrease the font size of xterms when moving them to the right
column. I wonder if someone could point me to the right direction. The info I
guess I need is

    a) how to change the font size of an already open terminal from another
       process
    b) how to detect in wmii that I move a xterm to the right column and start
       a process that does a)

regards,

-- 
Iván F. Villanueva B.
FFII (open standards, no software patents)  --  http://www.ffii.org
FFII.org Deutschland                        --  https://www.ffii.de
Jabber: ivan_AT_ogai.org