Sort TV Shows by Season and then Episode

Hi guys,
probably this has been asked before, but I spent hours on google now and could not find any solution.

I am using a twonky server (Twonky 7.0.8 Special) on my D-Link DNS 323 NAS storage.

Mostly I am using this to watch my (quite large) collection of TV shows. I named the files like

[Show Name] - [Season]x[Episode] - [Episode Name]

All shows are in MP4-Format.

Without having iDentify (some Mac software) fill in the tags, the file name applied for display and sorting.
Now it takes just the episode name for *both*!

The effect is easy to imagine.

01x01 - Zoo
02x06 - Bear
04x01 - Ape

now becomes

Ape
Bear
Zoo

This messes up the order series are played of course.

As a software developer I did not hesitate to edit the view-definitions.xml (most users will!).

I added the attribute "sortcriteria='+upnp:originalTrackNumber'" so now it at least sorts by episode number.

However that only solves a part of the problem.

01x01 - Melissa
01x02 - Jane
02x01 - Anita

becomes

01 - Anita
01 - Melissa
02 - Jane

I really want to sort (and if anyhow possible display) my videos the way I named the files!

Is there a list of tags that can be used?

Really, this is everything but user-friendly!