advise on a new config style

I've worked out code to do a set of regular expression substitutions on source/destination addresses.
now I just would like  to make it configurable, so looking for any advise on  modding cfg etc?

the idea is like...simplest example....

source-addr-regex-subst = "^([2-9][0-9]{9})" "1$1"
                                            = "^0([2-9][0-9]{9})" "1$1"
 
for any number of regular expressions and substitions - one per line

I've only started to look at the cfg code, theres some weird stuff in it....I now wish to make config  xml based!! lol!