Using same Outlook Express with 2 OS’s

I ran my computer with Windows ME and then installed XP on the same computer in a different partition so when I boot up I can use either ME or XP. Is it possible to use the Outlook Express with all my messages from Windows ME with XP when I go on line with XP or do I need to transfer/import all messages from ME OE to XP OE? It would be great to use the same OE.