Deleting Sheets without losing Reference In a Formula

I'm not sure if I'm explaining this clearly, but...
I'm creating a report that references an database exported excel file. The problem is I need to replace several worksheets with Year-to-date numbers.

Is there a fast way of deleting an old sheet and replacing it with a new one without removing the sheet reference in a reference formula?

ie. New Sales (from May) replace with New Sales (from June) without haveing having the vlookup give a #ref error in the sheet reference.
Thanks!

I'm having a similar problem. I have a summary worksheet that uses the SUMPRODUCT function with references to a data worksheet. I need to replace the data worksheet without the SUMPRODUCT function producing #REF errors. The new data worksheet contains the same formatting as the previous worksheet. I've tried setting the Calculation option to "manual" but it did not help. I've looked for VBA and VB code to no avail. Have you found a solution?