Locked spreadsheet

We are a manufacturing company of energy management products that we sell to dealers across the country. We have created a 43 page spreadsheet with proprietary formulas in it using Excel 2011 for Mac. It is used for grocery store energy audits and we want to make it available to our product dealers via our website. All of the tabs are locked so that only the unlocked cells are editable (none of the unlocked cells contain formulas) and the workbook is locked so that tabs can't be moved, deleted, etc. The dealers will be paying a monthly fee to use this spreadsheet. One option we were thinking about was to have a link to the spreadsheet so the dealer could open it up in Excel on their computer, put in the necessary info, print tabs as needed, etc. We don't want them to be able to save the spreadsheet to the point where they could delete the info out of the unlocked cells and put in new info. However, they may need to change info they already entered if the customer changes their mind on what they want so that the resulting quote that is produced by the spreadsheet is accurate.

So we want the spreadsheet to be usable, printable, and savable, but not too savable. I'm hoping someone might have a suggestion on how to accomplish this either through linking the spreadsheet to our website or a third party website that would "host" our spreadsheet, or any other method that this could be done.

Thanks!

Thanks Paul, that's what I figured. I will do some searching for the free products and talk with our web designer on the best approach.