Create an Infopath form to generate unique number MOSS 2007

I created an infopath form that would auto generate a number to each form from following instructions at the following site.

http://enterprise-solutions.swits.net/browserforms/autonumber-infopath-form-submitted-sharepoint-library.htm

I am wondering if it is possible to change the starting point of the ID field within sharepoint.  It starts at 1.  I would like it to start at 1000. and add 1 number each time a new infopath form is added. Or would I add a different field to accomplish this.