Default [Q] modify system file to setup VPN

I had root, however i want modify my system file(or database) to add new vpn , i know i can do it manually , however i want to do it programmatically, so im wondering what file i should modify to set up a VPN? someone knows this?
Check Out this apps
Car Dashdroid, A car dashboard rate if you like
SMS enhancer, check out the XDA thread

fix google security flag with my app
https://play.google.com/store/apps/d...creenprotector

Nexus 4
HTC One X
Samsung Galaxy Pro
HTC Evo 3D
Motorola Atrix 4g
NeXuS OnE (Retired)
My First Android:Nexus One: 05/06/2010