How to pass a Named Range from a cell as an argument to a formula

Hi,

I have the following formula which works fine in this form:

=vlookup(H2,GradingMatrix1,2)

where GradingMatrix1 is a Named range.

I have other named ranges GradingMatrix2, GradingMatrix3 that I would like to pass to the formula depending on user input.

If a cell, say A2, contains a value "GradingMatrix1" and I convert the formula as follows:

=vlookup(H2,A2,2)

then (unsurprisingly) the formula considers the array argument to be the single cell A2, and not the named range referred to in the cell contents.

Maybe somebody out there could suggest a method of passing the range named within the cell as an argument to the formula?

Many thanks
B.