Alright fair enough man. Sorry for being a dick I thought you really were one of those people that believe this kind of work can be done with a simple line of code.
The rough outline for a CTF style gamemode would probably be:
You'd want to first of all code in an extra score keeping system so that you can keep track of what team has captured how many flags.
Then, you'd have to code in two [or more] flag entities that can be picked up, one for each team.
Then finally, you'd have to code in two [or more] flag base entities that would allow an opposing team to actually capture the enemy flag and get a score.
To be honest I don't think any of this would be particularly difficult, you'd just have to sit down and connect them all together in a way that works. Good luck.