Lead uploaded via Data Upload but not given Incremental ID

Hi,


Some background to the issue;

We've altered our eware_default_values Stored Procedure to assigned custom incremental ID's to Leads. When creating a lead through CRM it assigns an incremental ID. However, the Leads created via Data Import do not have an Incremental ID. I understand that this is by design as per Jeff's article here.


My question is, is it possible to assign these Leads, created via Data Import, an incremental ID. I've done a bit of reading and noted that just setting values in those fields has the potential to 'break' things and throw up the following error - Cannot insert duplicate key row in object....


Is there a safe way to do this?

Thanks,

Will