Creating connecting shapes
 

Hi-

Does anybody know how to create custom connecting shapes? I'd like to use something like the following:

[IMG]http://dl.dropbox.com/u/3910149/doublearrow.pdf[/IMG]

as a connecting line rather than a grouped shape so that it stays connected, etc, etc when I drag things around. This seems like what connecting shapes were designed for but I can't figure out how to make 'em. I guess I want to make a grouped object out of these two arrowed lines and then add a green and red line end handle to it..

Cheers,
Chris