Create and Virtuemart Gift Voucher within existing site

Need to add a Gift voucher option within virtuemart to operate similar to [login to view URL] Want to be able to nominate a $ amount. An email is sent to the recipient with an automatically generted Redemption code. The payee then goes through the existing shopping cart to pay for the Gift Certificate amount. Need to also add Tell A Friend option to operate same as [login to view URL] as well as Share option as [login to view URL] There will be client alterations. All code must comply with existing website.