App that adds attachments from within reply or forward message.

I'm new to the iphone. So far I'm loving it. The one exception is the It doesn't allow me to attach a file if I am doing a reply or a forward of a message. I have to go and compose a new mail in order to attach a file.
This makes me loose time if I'm replaying to people who are not in my contacts as I have to manually copy each one of them to the new compose message.
Any clues?
Thanks for any orientation in the right direction.