[Tilecache] Tilecache and MapServer variable substitution

[Guillaume Sueur]

Hi list,

I've noticed that MapServer variable substitution doesn't work with 
tilecache as it doesn't transfer the non standard parameters to 
MapServer, either with WMS layer or MapServerLayer.
As I need this functionnality to work, I plan to add it to tilecache. I 
have seen the WMS-T thread and patch which is a good starting point.
Is there any further hints/advices/caveats I should be aware of before 
screwing all the thing up ?

Thanks

Guillaume