Excel 2003

I am using formula below succesfully , but I need to expand on it

=INDEX(K3:AM30,MATCH(A4,K3:K30,0),MATCH(A5,K3:AM3, 0))

What I have is in K3:K30 is a range of numbers 0,6,11,16,21,26,...

I also have in L3:L30 is a range of numbers 5,10,15,20,25,30 ...

0 5
6 10
11 15
16 20
21 25
26 30

Then there is a range of static data filling in the rest of the array

I need to modify the MATCH(A4,K3:K30,0) portion to look at the L column and
K column and pick row that the value in A4 equal to or between.

The above formula will work if I put into cell A4 the exact number that is
in the range K3:K30, and ignore the value in L3:L30.

I need the formula to work if the number 7 is entered in A4 the same as if 6
were entered into A4

In other words I need the match to work on = K3 and <= L3

Thanks,

Gary