Extent Sizing in Online 5.08?

I am hoping someone could help with a few Online questions... I noticed in dbaccess you can specify the initial and next extent sizes when creating tables. I found the results in the systables database. How can you set these values from within a program? I could not find a command to add to "create table" or "create index"... I read that "ALTER INDEX".."TO CLUSTER" will reclaim deleted space. I have a table that had 400K rows deleted and I'd like to pack it. In the dbaccess help I could not find this command. Is this a 7.x feature (my manual says 5.0?) If I get it to work, will the index remain a cluster index? Finally, in SE there was a program called "bcheck". I am aware of "tbcheck" in Online. Is there a way to get tbcheck to rebuild all indexes as bcheck does in SE? I could only get tbcheck to report extent problems and no critical errors. Thanks in advance!