If you can stand putting the entire line with the delimiter in the new file, there's a quick and dirty version for this: 
perl -pe 'BEGIN { $x = "aaa000"; } open STDOUT, ">".(++$x) if /XXFFDDF
+/' <input >initial_output

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-- Randal L. Schwartz, Perl hacker

In reply to Re: Answer: How do I split a file into parts by merlyn
in thread How do I split a file into parts by Anonymous Monk

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