[Radiant] Best way to modify default load paths for extensions?

[Wes Gamble]

 I have an additional path that I would like to be on the load path for 
a given extension.

What is the best way for me to add this load path to the set of default 
load paths in Radiant?

Do I need to modify the load paths for _all_ extensions or just this one?

Thanks,
Wes