[decoders] best practice for decoding grib

Greetings,
 
I wish to learn how to...
 
1. Query muliple grib files simultaneously to define and retrieve data 
spatially and temporally (e.g., by latititude/longitude and by date/time).
 
2. Dump the results to a comma-delimited text file
 
The types of grib files that I am interested in accessing are those found 
here...
 
ftp://polar.ncep.noaa.gov/pub/history/waves/
 
Is there a grib decoder, perferrably one that works in an MS Windows 
environment, that would allow me to (a) query many files at once, (b) decode 
only the data for a specific lat/lon and within a specific date range, and (c) 
dump the decoded data to a comma-delimited text file?
 
If anyone can point me to a tutorial with an example of the procedure using the 
appropriate software, that would greatly help.
 
Thanks kindly!
 
Cheers,
Joseph Spain
Research Meteorologist