Returning 25th to 40th result of SQL query, do I use a cursor?

Question

I have a complex SQL query that returns ALL the results I am looking for. I would to be able to only return the Nth to Nth result, like just the 50th to 70th record counts (assuming there is a sort by in the statement so it always returns in the same order.)
I thought of using a cursor and checking %ROWCOUNT and only returning the proper rows, but that seemed like it would be inefficient. I could do the same on my front end (PHP 4.0.6) relatively easily, but that would be a really inefficient way to retrieve 20 records from a query with 1000+ records returned.

Answer 1

Thanks, the links were helpful.
Since rowcount ignores my order by clause, I have attempted to find ways to overcome this. I have tried using the rowcount method by recreating my tables as index-orginized with an index on the column that I need to be ordered by. As a result of this, I have come accross two problems.
1. then index does not seem to update the order when I update the column. The column being indexed is a date type. The values added are usually sysdate, so although new elements are added properly, updating old ones does not change their index position.
2. I really need to access the items from most recent to oldest, thus desc. Since I am returning by rowcount, this makes it difficult. The following SQL is the best I can come up with and requires the output to be looped in reverse for display in the correct order:
select postid, subject, to_char(lastmod, 'Month FMDD, YYYY HH')||':'||to_char(lastmod, 'MIam'), name from (select t.postid, t.subject, t.lastmod, r.name, rownum ro from forumtopic t, forumrooms r where t.roomid = '1000668' and t.roomid = r.roomid and r.useraccess = '1') where ro between ((select count(*) from forumtopic subt where subt.roomid = '1000668')-40) and ((select count(*) from forumtopic subt where subt.roomid = '1000668')-25);