This is my slightly more modififed version

Code:
/findline {
  window -hk @FindLine
  loadbuf 0 @FindLine $1
  var %line = $fline(@FindLine,* $+ $2 $+ *,$iif($3 == $null,1,$3))
  window -c @FindLine
  return $iif(%line == $null,0,%line)
}


$findline(mirc.ini,sounds,1) returns 33
$findline(mirc.ini,sounds,2) returns 34
$findline(mirc.ini,sounds,0) returns 6 (how many 'sounds' there are in total)

... just add it to aliases and play around with it yourself. :P