gnus can't later find server if starting off-line ?

gnus can't later find server if starting off-line ?

[Unknown]

I can't find a group specifically for gnus.
Are there any ?

I've started using emacs because of the split-screen-facility.
Very few non-trivial text-jobs can be done without having several
files open and editable at one time ?
You need to cutNpaste between files.

So I tried to use gnus too. Posting was OK.
But I get a <can't open server> error-mesg., for fetching,
except if I go on-line BEFORE I start gnus from emacs.

This suggests that gnus contacts the server as soon as it starts,
instead of only when you call for an action which would need
to access the server.

This makes no sense to me !

A painfull search through the help/s-FAQ lead to a lisp 'command':
 (setq  <args to set nntp-server>).
I've done some coding in lisp, years ago; but I can't see how/where 
to enter the s-expresssions ?! And I would expect an output from
any successfull 'setq' s-expression, OR an error response-mesg ?!

What am I doing/assuming wrongly ?

TIA,

== Chris Glur.