apt-get: upgrade one package to particular version?

[carlf@panix.com (Carl Fink)]

I've installed apt-get.  It works great . . but.  (You knew there was
a "but" coming, right?)

If I want to upgrade one package, e.g. icewm, to the version in
unstable, the only way the man page seems to permit would be to edit
/etc/apt/sources.list so apt would look for *everything* in unstable,
install that one package, then re-edit the file . . . which would also
require running "apt-get update" twice, right? 

The man page makes it clear that you can't give apt a version number,
so is there any other way to tell it "I just want this one package
from unstable, not everything."?

For that matter, what if I wanted an *older* version for some reason?
Would I have to specify that in sources.list as well?

Thanks for any answers.
-- 
Carl Fink		carlf@dm.net
Manager, Dueling Modems Computer Forum
<http://dm.net>