Macro for autofill address in excel 2007

Hello,
i am using excel 2007 prepare my sales invoice, i have maximum 10 to 15 purchaser, so i
am using validation for selecting purchaser. i have the purchaser details (address,zip, contact) in another sheet , so i need macro to auto fill the address after selecting the purchaser form drop down list.Because i have used V-lookup but its not working after copy and paste of invoice in another cell.

thanx,
if u will forward my answer step to step i will be highly obiliged to u.

Prahalad