The first solution that comes to mind is to have "someone" manually create the account in both places (MSAD and ZCS).
There's an
ongoing thread regarding the subject and there's also a
bug filed, that you can vote for.
Another option is to find a way for a script/program/cron job to ask MSAD to show you changes made in the past X periods-of-time and create new ZCS accounts based on that via zmprov or otherwise. Tell your users "accounts take up to H hours to fully activate in our systems"...if that's feasable.
Or you can look into tools like Novell's Identity Manager or Sun's (er, Oracle) Identity Manager that would create the account in both places for you.