I'm not sure if this is possible or not. I have a spreadsheet that makes
calculations based on the distance between two zip codes that are entered by
the user. Right now I'm using a table listing each zip code and it's latitude
and longitude, and a formula for the distance between two points on a sphere.

What I really need is the distance by road between the two zip codes.

So, is there any way that when something happens (a macro is run, or a value
is entered in a cell, etc.) that excel can take the two zip codes that the
user entered and plug them in to google map's driving directions, and then
return the number of miles that google maps provides to a third cell?

Thanks in advance,