How can I get a postal code in a cell - from the internet?

[Guest]

I'm trying to insert a postal code into a spreadsheet based on the address
information we are given. I need a way to use the street address, city and
state to plug into a message to a lookup table on the internet so that I can
get the ZIP code back to insert into the correct cell on the spreadsheet.

 

[Guest]

Open:

http://zip4.usps.com/zip4/welcome.jsp

and enter the address information via VBA. The web page will return the 5+4
ZIP code which can then download.

 

[Guest]

I knew about the USPS site - and I've used it before to do this manually -
but is there a way to do this lookup in a spreadsheet cell? That is to say;
can I put a formula into a cell in a spreadsheet that will take information
from "address", "city" and "state" cells and extract the information from
another place and insert it into the cell?