Did it say it couldn't find mysqldump, or that it didn't like something about the parameters you passed to it? If it appears that it couldn't find the command, you could run the (cron?) shell command find / -name mysqldump -print 2>/dev/null and see if it finds something. It's always possible that command is installed where it isn't accessible to mere mortals. Once you find the command, mysqldump --help should list the options it will accept (-h, -u, -p, and the database name look OK -- if nothing else works, try a space between -h and the hostname, and -u and the user name, but not between -p and the password). Does LPCP use the same database name system (accountname_dbname) as cPanel?