Any way to obtain a piece of merge field?

[Colin Higbie]

I am working on my merge, and I want to be able to extract the first letter of
the First_Name field to obtain the first initial. In other places, I want to
be able to extract a number from a date in order to calculate timing of
certain events during the merge.

Is this possible? In WordPerfect, I can use a Substr(Field_Name, 1, 1) which
means starting at the first character, extract 1 character. Is there any
equivalent to this in Word?

Thanks,
Colin