How can I modify the login form header?

[sphynx]

Hi there. I would like to "synchronize" my website's design with the Roundcube's for a smooth transition between them. Basically, I'd like to change the Roundcube logo in the login area with a more complex header, with my site's logo & links. The question is: where do I paste my code? Is it a CSS thingy, or it resides within the index.php?

Thanks for your patience. Sorry for my lack of coherence; i'm not a native English speaker.

[sphynx]

OK, I figured it out. One can accomplish the above-mentioned task by modifying login.html in skins\default\templates\ directory. Next time I will make sure that I have tried everything before posting. Thank you anyway