Installing lang files for gtksourceview

Hi all ... is there a way to detect where .lang files are installed?

i'm using GtkSourceView in an internal Netlist editor in a schematic
capture aplication and need yo know where install the .lang. I try with
pkg-config but it not set any preprocesor variable to know the path, and
i won't assume that files are installed in /usr or /usr/local ... and
install one file per user in ~/.gnome2/gtksourceview/* is not a
solution :-)

I will appreciate any help.

-- 
Ricardo Markiewicz // http://www.fi.uba.ar/~rmarkie/