Excel - my turn for help
 

I'm knowledgeable in the use of Vlookup. In this specific case - first time I'm trying to do this - I want to use two numbers in two different cells as part of the lookup range.

Example
A1 contains "500" = this represents the start row 500 in a data array C:Z on Sheet 2
B1 contains "1000" = this represents the end row 1000 in the same data array C:Z
These 2 values change based on data in the C:Z array - via different formulae. They might be 500,1000 today, but 750,2000 someday next week. That is solved.

A10 contains a value, I want to return a value from the C:Z array column D that corresponds to it. My Vlookup formulae without using A1 and B1 would currently be =Vlookup(A10,'Sheet2'!C500:Z1000,2,0)

How do I inject the value of A1 and B1 into the vlookup formula?

Well _ I should have known as soon as I posted the question, I'd figure it out.
The answer is use of the INDIRECT function.