Triggering ganttproject-2.0 from XFce4
 

I have downloaded Gantt Project (Project Manager suite) and as it is a java-based programme it only allows one to start the programme once one cd's into the ganttproject-2.0 directory and enters sh ganttproject.sh .
Now that's fine, but I was wondering if there was a way of starting it using some of the panel menus in XFce4. This usually works fine for programmes installed in /usr/local/ or some such, but doesn't work for the Gantt Project programme because of the need to cd into the directory first before entering the shell script.
I hope the above makes sense? Anyway, does somebody have a suggestion about how to start the programme from a menu rather than from the command line? I have tried commands like: sh <directory-that-holds-ganttproject>/ganttproject-2.0/ganttproject.sh and variations on this theme, but nothing will work unless one is in the actual ganttproject-2.0 directory before the sh ganttproject.sh is used.

Any ideas??