[Request] Report Abusive Private Messages to admin

Hi

I am running ConnorHDs Private Message mod and wondered if there was any who could hack the mod a little to add an extra feature?

I need an option for members to report spam private messages. Just a simple 'report to admin', so that the PM in question will forward along to me to read... Then I can ban whoever originally sent it.

I know the point of Private Messaging is for them to be Private, but if someone complains about a spam PM it is there word against the accused spammer.

Is this a needed mod, or am I overlooking something simple which allows me to do this already?

Thanks