Without having the forum pull data from the archive database, no. As the two programs are incapable of being bridged as it is. What you're talking about would be rewriting an entire subroutine within the files which control the skinning options. It's just as likely that by doing that, I'd make something not work right in the forum.
What I can look in to, is the possibility of making a hook for the custom field instead. A hook, once written, can be enabled/disabled, without causing problems throughout the forum. However, that's very low on my to do list.
The quickest fix, is a formatting fix, within the skins. Again, you're talking a fair bit of time tracking down exactly WHERE in the skin I have to do this.