As for GUI, no way. The big advantage of this program is its simplicity and LACK of GUI.
The modified sources, and also the executable, are here:
http://www.sendspace.com/file/ra2psh
The additional flag is -g and you give it the name of an nzb file to generate.
I tested this against astraweb and giganews.
There is some problem with astraweb, it seems that sometimes, for no apparent reason,
the server rejects my message-ID and replaces it with its own.
When this happens, it happens for ALL the parts the file is broken into.
I must generate the message-ID's myself, since NNTP protocol doesn't give back
the messsage-ID after a POST (and I didn't want to get into reading back headers).
I make up the message-ID as per recommendations, with a random string.
I checked that when this happens, the message-ID is not a duplicate of a previous one.
It should be noted that this doesn't seem to happen with giganews,
and also, that it DOES seem to happen also with YencPowerPost-AA (windows).