Age Difference Date/Time Field

First time doing this so if this is a ridiculous question my apologies.
Is it possible to fill the field Age field automatically and/or on Merge to
a Word document using a macro?

Table: Contacts

Birthday Date/Time
Age DateTime update each year on output according to Macro?

Where does one put the code for Age field to generate the current Age field
automatically if one can based on the date in Birthday field.

If I merge AGE I expect it to put 32 if person's BIRTHDAY field was 32 years
ago? Can I put a macro in the field?

Age:
DateDiff("yyyy",[Birthday],Now())+Int(Format(Now(),"mmdd")<Format([Birthday],"mmdd"))

I want the field to calculate age. I can achieve it in a report but can I
apply it to a field?

Many thanks.


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