VB code query multiple outlook accounts from excel to find out of office dates

im looking for some pre-existing VB code or pointers to some that i could build on to incorporate into a button in excel in order to ascertain the out of office/vacation dates for selected people from their outlook calendars. this, in turn is going to be incorporated into a larger application as a way to prioritize the sending out of results based on the state in/out of office state. any help would be great, thanks!