Best way of identifing calendar items via permanent id using EWS via SOAP

Hi!

I am currently working on a simple tool to "create", "change" and "delete" calendar items over EWS (Exchange 2010).

Creating an calendar item i get an "ITEMID" in the response of the webservice. While reading in different forums it is not recommended to use this ITEMID due to the problem that it can change over time (exchange security patches, moving a calendar item,...).

Does anyone have a simple and valid solution for the problem e.g. using an other id like the "GlobalObjectId" and if yes how would this work?

how do i get the "globalObjectId" of the created calendaritem and how can i find my calendaritem via SOAP using the "globalObjectId".

I read a lot about this on different forums but couldn't find a solution that works. Thanks in advance for samples GETTING the "globalObjectId" and FINDING via "globalObjectId"

cheers,

bastian