Code:
on *:text:*:#:{
  if $left($1,1) == <ctrl + k> {
    var %fore = $gettok($1,1,44), %back = $gettok($1,2,44)
    if %back !isnum {  %back = 0  }
    if %fore == 0 && %back == 4 {
      <rest of code>
    }
  }
}


UNTESTED