Attach invisible data to a TreeRow?

[Matthias Kaeppler <matthias finitestate org>]

Hello,

I was wondering if it's possible to attach additional, invisible data to 
a TreeRow in a ListStore. I'm not talking about any actual values which 
are visible to the user, but some form of meta data which can be used to 
relate the row to certain other data in an efficient way (e.g. through a 
pointer).
I need this kind of funtionality to map filenames in display format to 
actual filenames on the disk, in order to avoid having two containers of 
filenames, one holding the actual names, the other the names in 
displayable format (this would introduce a lot of redundancy).

I thought about deriving from TreeRow and add a new data field, in fact 
a pointer to the real filename which matches the displayed name in the 
row, but that doesn't help because ListStore creates the rows for me 
using append().

Any ideas?

Thanks,
Matthias