I have a table like below:

A B C D
X 1 2 3 5
Y 6 7 8 9
Z 10 11 12 13

with names defined by top row and left column. If I input in a cell the
formula "=X B", it will give the intersecting cell's value - 2.

If now in two cells I separately put X and B (say D1, D2 respectively), is
it possible to write a formual that get the cells' content and interpret it
as intersecting names - i.e. give 2? I tried "=D1 D2" and it gives a #NULL!
error.

Thanks in advance!