I have looked for a way to sync both on the same BB and cannot find an easy method due to the difference in setup of each. In most cases the LN layout does not match MS OL and this may be an issue.
One other issue may be if your company allows personal contacts on the company bb. You do realize these can be know by your company along with other item on the BB as well as usage.
I have attached two possible RIM support links that may help.
Welcome to the Forums. KB03060-How to configure BlackBerry Desktop Manager to synchronize with multiple Novell GroupWise contact lists KB18080-Configuring synchronization for multiple contact lists with BlackBerry Device Software 5.0 on BlackBerry Enterprise Server 5.0