any screenshots you can post to see where you are not having success? have you looked in the relevant section of the admin guide?
Common Components Administrator Guide : Monitoring SNMP Traps : Using the Trap Viewer : Configuring Trap Viewer Filters and Alerts
Admin guide link - http://www.solarwinds.com/netperfmon/solarwinds/wwhelp/wwhimpl/js/html/wwhelp.htm#href=OrionAGTitlePage.htm