Problems creating a dropdown box (data validation)...

We've got a dropdown box (data validation - list) which is picking up data from a specific column. The data in the column is in the following format:

1 Sales
2 Contracts
18 Opening Stock
27 Purchase
etc

When we select an entry from the dropdown box the cell obviously displays both the number and the text description to the right.

What we need it to do is just display the number after selecting an item from the list. The text is descriptive and to make it easier for users.

Is there a way of configuring the dropdown box (or another way) so that say if a user selects "1 Sales" from the dropdown it just displays "1" in the cell.

thanks in advance.