[Proj] Proj command usage

[Herve Baille]

Hello

New in this list.
We are changing our own projection functions for a standard tool, 
libproj4, on Sun Sparc Solaris 10.
We project (latitude=45, longitude=0) to a Lambert conic conform 
projection called "extended Lamber II" used in France.
Our program gives (x=415728.737817, y=2002668.173285), which is very 
close to the result of the National Geograpgic Institute.
The "proj" command (with correct projection parameters):
echo 0 45 | proj +proj=lcc +lon_0=2.3372917 +lat_0=46.8 +lat_2=45.8989 
+lat_1=47.696 +x_0=600000 +y_0=2200000 +ellps=clrk80
gives:
415663.74       2002665.67
We are not very far on Y axis but 65 meter away on X axis.
If I specify the XYZ offset between WGS84 and NTF (dx=-168, dy=-60, 
dz=320) with option +towgs84
the command:
echo 0 45 | proj +proj=lcc +lon_0=2.3372917 +lat_0=46.8 +lat_2=45.8989 
+lat_1=47.696 +x_0=600000 +y_0=2200000 +ellps=clrk80 
+towgs84=-168,-60,320,0,0,0,0
gives exatly the same result
415663.74       2002665.67
as if the option +towgs84 is not used.

Where could be the mistake?
Is there an other way to specify the translation?
Thanks
Herve