where to store vhost options

[myanushurts]

Hi all!
I installed RC2c and i am currently trying to use a vhost to proxy connections to a Plone Site. In order to achieve that i have to add a directive a la
ProxyPass / http://localhost:8080/VirtualHostBase/http/domain.tld:80/Default/VirtualHostRoot/
ProxyPassReverse / http://localhost:8080/VirtualHostBase/http/domain.tld:80/Default/VirtualHostRoot/
to the vhost. I cannot enter these details to ispcp.conf since my details will be overwritten whenever the file is regenerated.
So my question is: Where should i store my additions for inclusion?