$flags = SCINTILLA_FIND_DOWN +
         SCINTILLA_FIND_WHOLE_WORDS +
         SCINTILLA_FIND_MATCH_CASE +
         SCINTILLA_FIND_WHOLE_WORDS +
         SCINTILLA_FIND_WORD_START +
         SCINTILLA_FIND_REGEXP;

$what = 'text to find';

// start and end positions...
$start = 0;
$end = $scintilla->get_length();
$result = $scintilla->find_text($flags, $what, $start, $end);