dted files

  Hi All,
I'm sorry my mail may be out of topic, but I would like to read dted
files I got on http://164.214.2.59/geospatial/products/DTED/dted.html

It looks like Grass allows that, but it sounds quite complicated to me (I
never used any topographic tool). What I'd just like to do is to have the
altitude of some [longitude,latitude] points (in order to propagate
neutrinos in the mountains).

Is there somewhere some C routines to read these dted files and get the
data ?
Thanks in advance,
--
Xavier