Limit the number of simultaneous connectios that an athenticated user can do in Apache 1.3.29

Hi all!

I have a server with apache 1.3.29 and I would like to limit the number of concurrent conections that an authenticated user can do simultaneously (a logged in member) to prevent the overhead of download managers placing i.e. 20 connections per download file.

So let's say I would like to limit the maximum number of concurrent connections to 4 per user. How can this be done?

Thanks in advance!!
Demien