Securing Zap*.conf files on reboot

I am trying to set up AsteriskNow for use on Cnet, the Legacy telephone equipment network.

AIUI this requires non-standard Zaptel & Zapata conf files, but despite both making them read only and entering my desired channel settings in the Zaptel & Zapata conf.zapscan files, when AsteriskNow boots, it enters it’s own parameters ( having made the files writeable ) causing subsequent errors on boot up.

Is there ANY way that I can prevent these files being over-written. Apparently it doesn’t happen if you use a combination of Fedora Core and Asterisk, which looks like it the only option, though I was hoping AN might provide a one step option for similar enthusiasts.