Diana,

I guess I added to your confusion... I will try to clarify.  Your CAN use
the policy set "trick" to flip between modified and absolute;  that's about
the only option that will help for a single-node-name solution.  Any other
attributes that are changed in the copy-group could adversely affect the
desired version count subject to expiration.

So, in your example, you could (once a week, when you have the cycles to
handle) activate a policy set that sets "absolute" for all nodes in that
domain.  Then on Monday, re-activate the normal policy set for "modified"
incrementals.  Assuming you have identical ve/vd/re/ro parameters, with
ve/vd both = 30, you will have 30 versions (max) of any given file, for up
to re/ro number of days.

I hesitate to recommend this approach, because the granularity of control is
at the policy domain level.  I would (firstly) question why your customer
needs to run TSM as if it were Veritas or Legato;  full backups this often
are unnecessary under TSM, due to its progressive incremental technology.
If you must run periodic full backups, I would do it using an alternative
node-name... so you don't get hurt trying to complete the backup in a given
24-hour cycle for ALL nodes in the domain (you'd have node-level
granularity).

Hope this helps.

Don