Simple Cartesian Objective Analysis

Dear GEMPAK enthusiasts,

Please forgive me if my question is too fundamental, but it is one that was
not immediately answered by a cursory view of the GEMPAK tutorials and help
pages.  I am a novice user of GEMPAK, and I am wondering before I go too far
with GEMPAK if GEMPAK does the following simple procedure.  I am looking to
interpolate irregularly spaced data on a 2-dimensional Cartesian plane to a
grid in the same plane.  My desired interpolation technique is the Barnes
objective analysis, which GEMPAK obviously uses.  However, my study is
rather small-scale compared to the prototypical synoptic scale studies that
GEMPAK is often applied to.  Because my data already exist at prescribed
(x,z)=(horizontal,vertical) positions and do not concern the geometry of the
earth, nor are the data at "stations", it seems at first glance that my
application isn't easily suitable for GEMPAK, which cares about data in
latitude/longitude format and seems to require a list of stations.  Are
there GEMPAK routines that I somehow glanced over that can do a quick Barnes
Objective Analysis on simple Cartesian data without some convoluted
procedure?  If not, does anyone recommend a common software for this
purpose?

Thank you in advance,
Chris Rozoff