Mystique Ad in Header

I am trying to figure out how to place an ad in the header… I was able to replace the title with my logo. I was able to get rid of the tag line as well. Now I want to fill the empty space with an ad (728×90). If I can have control over the content that I add there, that would be great.

I have also tried to set up an adsense ad, but it appears on the next line. I want it to be inline with the logo. I was able to get an ad in the header but I was unable to center it (horizontally and vertically).

Any suggestions to either way of posting advertisements in the header would be great, thanks!