how to change the main header title in Vbulletin?

[Rick Sample]

I want the header to by dynamic so I coppied my forums source code and played around with it like that. I then got it to be dynamic, but before I upload the new header image, I need to figure out how to change the coding. Is their a spot in the admin CP somewhere?

Here is what I need to change it to:
<td background="vbulletin3.gif" width="100%" height="70" border="0" alt="Muscle-Mustangs.com Forums" /></a></td>

Thanks a lot,

[Rick Sample]

I think I got it! I just have to upload the image here when I'm done creating it now!