Hmm. I haven't found the need to use the new file handling commands, but I do believe iLLuMiNaT is correct from what I know about the API these commands use. /fseek simply lets you begin over-writing at a specific byte offset, not insert. You would have to fseek, read to a binvar, write your line, then write your binvar. If you wanted to delete a line, you would have to /btrunc before at the point you wish to delete and then write your binvar.
Edit: Sorry, I didn't notice you were talking about plain-old /write in your most recent post, so this only applies to your earlier post.
