Please Help : Perl Script to Make Dynamic Apache MPM-ITK Config

Dear all,

I have multiple users with their own /home folder. These users also
sub-domain of my server. for example :

mac.example.com >> /home/mac.example.com
max.example.com >> /home/max.example.com
taylor.example.com >> /home/taylor.example.com

by using MPM-ITK my Apache can be configured to access those folders with
UID and GID specified. not as www-data, Apache's default. and that's
exactly what I want. I want my Apache change its UID into mac, while
accessing /home/mac.example.com and so on...

unfortunately, Apache configuration file seems doesn't support 'variables'
to put as AssignUserId on my /etc/apache2/apache.conf

tons of documentation on the internet told me that the configuration should
be like this (STATIC) :

<IfModule mpm_itk_module>
AssignUserId user group
</IfModule>

until this Mod Perl gave me a little bit hope to make everything works... I
only have this 'clue' to make Apache config file runs dynamically :
http://serverfault.com/questions/75010/dynamic-authentication-realms-in-apache/75526#75526

but I'm not Perl-guy, I have no idea how to modify those codes to fits my
need. please kindly help me... thanks before.