I'm not sure this is the best way (maybe a perl expert can tell) but doing it your way, I made

my  $str = "12-APR-03 12:20:46.902801 IP 10.60.0.114.2684 > 10.60.0.3.
+110: . ack 3927995843 win 0" ;
if ( $str =~ /IP\s+(\d+\.\d+\.\d+\.\d+)\.(\d+)\s+>\s+(\d+\.\d+\.\d+\.\
+d+)\.(\d+)/ ) { 
  print "matched: $1|$2|$3|$4";
}
[download]

Cheers
LuCa