Prevent cert export on handheld?

[PatDubya]

Is there any way to prevent a user from exporting certificates from their BB?? I can't find a Policy setting for that, except where you use the CA auto-enroll, which we are not doing.

We have local encryption enabled, so I'm not worried about losing a cert if the handheld is lost, but we need to prevent a user from emailing it from the BB if possible.

Thanks!