I'm not sure about how to do as you request... but there may be an easier way. Project has a calendar wizard that can be used for that purpose, (takes about 5 minutes). Once you set up the holidays in the calendar one time and save it as "Company calendar" or something like that, you can then save it to the Global.mpt file and then use that as the basic calendar for all your projects. Hope this a better way to solve your issue.
Z.