I've accomplished this by used excel-as-middleware. I created a custom field on my object, Opportunity, to hold the version number. I then setup my DDP to use excel-as-middleware and an Insert-Update. The excel-as-middleware file is tagged to populate the current version number field from my Opportunity record and also contains an equation in the cell below to +1 to that number. I then tagged that cell with the calculated value and used it in the Insert-Update to update my record with the new version number.