>>I beleive without temporary PK you will get in trouble -
>>here if on the same day to bills happen to be in existance.
>>
>
>Building analogue of row_number() in VFP it's quite tricky (SQL 2000 also). It can be done with subquery, but I don't want to post this solution. If we have such requirement, build the needed output using scan/endscan logic in VFP.

In cases of building temp PK I go for single statements -
gave him one one join leading and one deleting the values...
guess OP did not grok it.