Sunbird: Relative path to ics-files?

Hallo everybody,

first I wanna say THANK YOU!
Your effort in making all these portable applications must be enormous so I just wanna thank you...

Now to my question / problem:

At the moment I'm setting up an event-sharing service for my association. For this I've decided to use Sunbird Portable.
Everything works great up to now. I managed to get the localised version (german) of Sunbird to be run by your starter. I created a default profile which can be distributed with SunbirdPortable.
For the service to function properly I plan to release updated ics-files containing the events via eMail, so I set up Sunbird Portable to load some calendars in this format at start-up (via "File --> Open calendar file").

My problem at this point is that these files are stored with absolute pathes.
For Sunbird Portable to be truely portable these files have to be stored with relative paths, but I don't know how to do that...

My Sunbird Portable folder looks like this:

+ Sunbird Portable
---+ App (contains the program files)
---+ Data (here is the profile)
---+ ics (the calendar files are in here)
---SunbirdPortable.exe

Is it possible to tell Sunbird to look for these files with relative pathes?
If so, how do I do it?

I appreciate any help...

Yours sincerely, Jan Schmitte