Position of Weblog title and tagline

I am in Option –> General (using Tiga template).

I have an image as Header Background.

I have written, too, Title and tagline, that appair in the left-top of the image.

I want Title and tagline to appair in the left-bottom of the image.

I locked, in the files of the blog, for the words contained in Title and tagline, but I could’nt find thet, so I guess they are in some data base….

How can I obtain title and taglines in the bottom of background image of the header?

Thank’s

Stefano