I am attempting to look up a particular value in a table and then identify
the number in the first column of that table which corresponds to that row.

For example:

111 678 666 475 987
232 565 687 4888 242
4543 123 3334 2727 590

From the above table, be able to enter a value in a formula within a cell
which in turn, would return the value in the first column of the row which
contains that value.
For example, if I enter the value 687 in the cell against which the formula
is applied, I wish the formula to provide the value "232" as the response.
Similarly, if the value 2727 is entered, the value 4543 should be the value
response.

Unfortunately, the lookup function doesn't work against a whole table nor
does it provide a value in the same column.

Suggestions? Many thanks.