Scripting Help for Ability Point Boost

[FCWesel]

Hello.

I am creating a template that gives a +1 to CHA at 5th level. How do I do that? I tried a simple bootstrap, but it doesn't work right there. Either it forces it as a 4/8/12/16, etc, Level bonus, which isn't right and messes up the level bonus point. Or it gives me a +2 bonus at the level I want, but I only want a +1 bonus.

A script would be fine, I just don't know how to do it.

Thanks.