retention policy for synthetic full backups ?

[workict]

I have a question, I created a daily incremental job within veeam.
That job is running a incremental backup from sunday till friday.
On saturday i'm running an synthetic full backup.

The retention policy I setup is 14 restore point, because I want to save 2 daily weeksets to go back.
But is it possible to keep the synthetic full backups for a longer period?

Because I want to save the weekly synthetic full backups for 4 weeks until a new monthly backup is created.
But is that possible to setup?

Or do I need to create a backup copy job to create a seperate week job and save that for 4 weeks ?

[veremin]

You can either increase the retention for a backup job, so that, it preserves the data for 4 weeks or add a backup copy job that will take care about prolongated retention policy. Thanks.