Movie tutorial on how to set up a database.
Then I believe its this info that Viper guestbook wants you to enter:
Databasename: yourcpanel_databasename
Username: yourcpanel_databasename
Password: your chosen password
Just a little addition to what Serpentine says...
On a regular account, Serpentine is correct, but I believe that on a reseller account you could do what you originally want.
I searched this and found a few places that discuss this (I think), see if this is similar to your case: https://lists.netfilter.org/pipermail/netfi...rch/059377.html