Would anyone be able to help me in the following??

I need to create a formula using indirect Vlookups to shift a data range
based on a month period.

For example: the current month being March 2008.
using a 12 month of sum of April 2007 to March 2008 - once it becomes April,
I will need it shift the range from May 2007 to April 2008.

I need to create a formula using indirect Vlookups to shift a data
range based on a month period.

For example: the current month being March 2008.
using a 12 month of sum of April 2007 to March 2008 - once it becomes
April, I will need it shift the range from May 2007 to April 2008.

Here's one approach, but it doesn't use indirect Vlookups.

Put the dates in column A, one month per row.
Put the corresponding amounts to be summed in column B.
Put the "current month" in C1.
Then consider the formula
=SUM(OFFSET(B1,MATCH(C1,A:A,0)-12,0,12,1))
Modify to suit.

(I have Excel 2003.)