how to use koji

[Michal]

Hallo Group Members

I am running fc12 and would like to get latest C++ boost 1.41*. I
noticed that they are present on koji.

I could use my firefox to get all boost packages from here, but 
is it possible to treat koji just as a repository to download packages
from.

I did some commands, like the following, but now I am stuck:


prompt$ koji help
Available commands:
...
        search                    Search koji
...
(Type "koji --help" for help about global options
 or "koji <command> --help" for help about a particular command's options

prompt$ koji search --help
Usage: koji sync [options] search_type pattern
Available search types: package, build, tag, target, user, host, rpm
(Specify the --help global option for a list of other help options)

Options:
  -h, --help   show this help message and exit
  -r, --regex  treat pattern as regex
  --exact      exact matches only
prompt$ koji search -r package "boost.*"
boost
pianobooster
mingw32-boost

prompt$ koji download-build boost
GenericError: invalid format: boost


what to do now????

best regards
Michal