Create an automated invoice

We need an automated invoice form created ideally in MS Word 2007 which will enable use to select products from drop down fields and populate and calculate the invoice correctly. There will be an accompanying spreadsheet which will contain all the necessary information. This spreadsheet will be updated periodically so the process needs to be dynamic. We will supply a mockup of the Invoice in Word format and a sample of the spreadsheet for development purposes. There will be a requirement for the invoice to work in both British Sterling and Euro and there will be separate prices in the spreadsheet - this will not be a calculation - so we will include a "currency" option in the mockup form. There will need to be an option to "email the form" once completed (as a PDF), to save it, or to print it. If you need to know anything else please ask and we will do our best to respond quickly. We do not have a large budget for this, but can stretch to £30; if it is going to be more than that we will use existing proprietary software we just wanted to make something bespoke for us.