For another colleague, Rien. Rien this is almost exactly the issue you have. Some differences are that you have 2 Microsoft exchange mailboxes and a private mailbox.

A growing number of people will be keeping their work calendars in Microsoft Outlook and their family calendars elsewhere, say on Google. How can they cross-publish their work and family calendars? It’s possible, but the conceptual hurdles are formidable. Here’s what I found when I did the experiment.

I started by subscribing a work calendar in Outlook 2007 to a family calendar on Google. From one perspective it was easy and just worked. From another perspective, I marvel at the amount of tacit knowledge required for me to have that experience. You start here:

Read the rest at the John Udell blog

Who can see which parts of my published surface area?

For example, I’m still working through the implications of the calendar cross-publishing arrangement I’ve set up for myself. Consider my Outlook calendar. It’s shared within the company by virtue of a default policy that I can view, or modify, by right-clicking the calendar in Outlook and selecting Properties -> Permissions. But it’s also shared with my family by way of a private URL that I created on my WebDAV server and transmitted out-of-band. I can see that private URL by right-clicking and selecting Publish to Internet -> Change Publishing Options, but there’s no indication there of who I gave the private URL to. 

This is an extract of the whole post