[horde] How to customize look/feel of Horde?

[Bill Moran]

I've searched to the best of my ability and haven't found what I'm
looking for.  I've got a suspicion that it exists and I simply haven't
looked in the right place.

Subject gives an idea.  A howto or beginner's tutorial to customizing
a Horde install would be a good start.  I've seen information on how
to create themes, but I don't think that's what I'm looking for just
yet.

My first challenge is to get the "Welcome to Horde" banner on the login
page to say "Welcome to <company name>'s webmail", and I can't figure
out what the correct way to do that is for the life of me.  Is there
a description of the Horde directory hierarchy anywhere, that will tell
me what files are intended to be customize, and which are considered
immutable code?

Any other pointers/suggestions are welcome.

-- 
Bill Moran
Potential Technologies
http://www.potentialtech.com