Delete own reply if last in queue

Hello,

Better late than never, they say…

OK, here it is, straight from a previous request:

Is it possible to allow deletion of a reply if and only if it is the last one in queue? This is a very common forum feature.

Example :

thread
reply #1 by user #1
reply #2 by user #2
reply #3 by user #1
reply #4 by user #1

I'd like user#1 to be able to delete reply #4, but not reply #3 (except once reply #4 is deleted, of course). Also, user#1 shall not be able to delete reply #1 and, of course, reply#2.

Does that make sense? Which modules are required and which settings are to be set?

Thank you.