That may not work if users are only connected for very brief periods of
time, if you are using randomization.  (I've been burned by this one, too.)
Because if the window is 12 hours, the server may give you a schedule that
starts 3 hours after you poll, and you may be gone and headed for your plane
by then.


You could set the COPY FREQUENCY of the backup copy group in the management
class for your laptop domain to 1.
That would insure that the data gets transmitted only once a day.
But, I don't think it will stop the dsmc incremental from trying to run and
searching all the directories a second & third time.
And sometimes there are legitimate reasons somebody wants to do a manual
push after the automatic backup runs, if they later make a bunch of changes.

Since you are kicking off via a batch file, could you:

check for the existence of a tiny file called tsmckpt.nn, where nn is the
day of the month.
If it does NOT exist:
        - create the tiny file called tsmckpt.nn
        - run your dsmc incremental
If it DOES exist:
        - you know you've been here already, don't run your dsmc incremental


At some point you would have to add some logic to clean up previous month's
tsmckpt.nn files.

I don't know if this is possible with the basic capabilities of a batch
file, as Winstuff is not my forte.

But if you don't mind installing ActivePerl on your laptops (it's free),
then  you can get fancy and do even more sophisticated stuff like save the
dsmc incremental output into dsmincr.log (you pick the name), have the perl
script read the tail of it to find out whether the backup already
ran/actually completed for today (after all, your user may pull the plug and
run for the plane while the backup is in progress - in that case you would
want to try again when he plugged in again).