Whilst the group is quiet a short diversion should not cause too much
distress !
(and I may be about to tell you a load of old b*&^% which someone may
spot, but not if I email you !! )
I'll try to be brief !!!

>I expected the file to just be attached as it would be in an email, but the 
>body was full of code. What's that all about anybody?

Binary files need to be encoded to transmit across the internet, both
in emails and as usenet posts.
The diference in your case, I suspect, is that your email software is
automatically recognising and decoding your email attachments ok,
transparently to you, whereas the newsreader is not.
I see that you have OutlookExpress, I dont use it but I am a bit
surprised that it cannot handle binaries on newsgroups.

Either
try another software
40tudeDialog (freeware) * is a good one that we use
http://www.40tude.com/dialog/

Or
it may be that Outlook doesnt handle the encoding that is popular now
in newsgroups, look for yEnc capability in your newsreader.
Perhaps there is an option to set, or a plug-in to download ?
Check the Microsoft database for OutlookExpress and yEnc.

Else,
if this has not helped you could try asking on
alt.usenet.offline-reader

* I may be out of date, I've not changed software in a long time,
there may be better than 40tude now.
check out alt.comp.freeware

HTH.