[gembud] Creating composite from tgftp.nws.noaa.gov

I'm working on a creating composites for the US using NEXRAD level III data
at 10 minute intervals.

I'm having a problem taking the data from NOAA's ftp site to the correct
location and file format in GEMPAK.

I would like to know how I can store and process data from NOAA's site:

ftp://tgftp.nws.noaa.gov/SL.us008001/DF.of/DC.radar/DS.p94r0/SI.<station
id>/sn.last

into GEMPAK using gdplot3, nex2img or ?

Thanks in advance for any assistance in this matter.

-John Coryat