Printing more spools with more copies the pages are mixed

Hi Experts.

By a z-program I can print at same time more spool files, each one has three copies.

The result that I get on the printer is: the first copy of the first spool, the first copy of the second spool, the second copy of the first spool, the first copy of the third spool, the third copy of the first spool and so on.

The spool copies are mixed!

I get the same result doing the same thing by SP01: i flag three spool with three copies each, then I push "print without modify" and I get on the printer all the pages ... but mixed.

I need to print all the spool together but in order: the first spool with its three copies, the second spool with its copies, and so on. Sometimes I have twenty or more spools: it's not very friendly to print one spool at time.

How can I get it?