HOW do you set UT3 to enter the game

i got a e mail to try this sniper game
DM SNIPER - 209.51.200.250:9999

were do i put the # numbers at?

<a href="http://www.gametracker.com/server_info/209.51.200.250:9999/" target="_blank">
<img src="http://cache.www.gametracker.com/server_info/209.51.200.250:9999/banner_560x95.png" border="0">
</a>