Hrm, I can give it a shot, though I'll need to make some test ones before, as I have tried to change the texture for the logo, but it fluxed it up
EDIT: Thuogh, if you want the Herocraft logo there, it shouldn't be too hard.
EDIT2: Here's a basic one with the Herocraft logo from your signature.
http://imgur.com/Ucxmm (mclogo.png)
http://imgur.com/F45VI (mojang.png)
in the 'splashes.txt' you can (use notepad++ or something alike) delete everything, and replace the first line with "[DH] Presents..."
Kainzo