Regular Expression Data Type

Hi.
I appreciate that I can query the database and find records that
match a regular expression.
What I'd like to be able to do is to define a field in the database
as a regular expression so that when I select, i.e.,

select price from shipping_prices where shipFromZip = '23773' and
shipToZip ~ '87927'

because shipToZip is defined as a regular expression, I'd match a row
where shipToZip held the value '879[0-9]{2,2}' or '87[0-9]*'.

Wouldn't that be cool? Does anyone know whether this is already
possible?

Thanks.