Adding custom template to another template

[Raw Sugar]

Okay, I'll be as descriptive as possible.

On my forum, I'd love to have an affiliates drop down box in the 'footer' in the middle of the style, links, copyright and all that. The only problem with having it hard-coded into the 'forumhome' template is that some styles have edited footer templates. Which means the drop down would have to be edited in each scheme.

I'm hoping there's a way to, either by php includes or some other way, I could have the drop down in its own template and call that over in the footer.

For the time being, I've settled with the affiliates having its own page, but it's very annoying and I'm sure no one goes to them.

So any and all help would be greatly appreciated! Thanks in advance...