DLM- appending removable disk storage

We have been using BE 2010 (and previous versions) for many years now.

We are currently trialing BE 2012/V-Ray in our test environment. There is no tape based storage, only removable hard drives (USB).
I have setup full and incremental backups with overwrite protection as follows:

• Daily Monday and Wednesday- 25 hours (incrmental)
• Daily Tuesday and Thursday- 25 hours (incrmental)
• Weekly (Friday night)- 6 days (Full)
• Monthly- 11 months and 29 days (Full)

Question: how can i set up append values? I want the:

• daily Monday and Wednesday drive to be overwritten on Mondays but appended on Wednesdays
• daily Tuesday and Thursday drive to be overwritten on Tuesdays but appended on Thursdays.

This would ensure that the second incremental backups doen't overwrite what was backed up to the drive earlier in the week.

Where do i find the append feature or how would I be able to achieve this?

Thanks!