Excel is not a database.

Are you trying to insert one particular address?  If so, how is the address
to be inserted determined?

If you are wanting to insert a whole series of addresses into individual
documents, use the Excel spread sheet as a datasource for a mailmerge.

See the article "Creating a Mail Merge Data Source" at:

http://www.word.mvps.org/FAQs/MailMerge/CreateADataSource.htm

See the article "How to convert addresses into a Mail Merge Data Source" at:

http://www.word.mvps.org/FAQs/MailMerge/ConvertAdrsToDatafile.htm

See the article "How to create a Mail Merge" at:

http://www.word.mvps.org/FAQs/MailMerge/CreateAMailMerge.htm