Vlookup, date range

I have a list of claims with the date of the claim. I need to put the year and fiscal period that the claim occurred in the column next to the date. In order to do that, I need help coming up with a formula. For example, if a claim happened on 2/15/12, that is in our fiscal period 01, so I need to pull back 201201 (year 2012, period 01). Our fiscal periods do not match up with calendar months, however. so, I think I need to use an if/then statement, something to the effect of:
IF the claim was between 1/29/12 and 2/25/12, THEN input 201201, but IF the claim was between 2/26/12 and 3/31/12, THEN input 201202, etc...

Can anyone help me with a formula like this? Or is there another way to do it that I may be missing?

There are several ways you could do this, but you will need to list your fiscal periods in a small table, for example:

1/29/12.......1
2/26/12.......2
4/1/12.........3

and so on. Suppose this table occupies X1:Y12, and your first claim date occurs in cell C2, then you could use this formula:

=YEAR(C2)&TEXT(VLOOKUP(C2,$X$1:$Y$12,2),"00")

which could then be copied down to pick up other claim dates in column C.

Hope this helps.

Pete