Drop down menu that shows option of another drop down menu.

Ok, I have a workbook with two tabs.

The first needs to have two drop down menus. The first drop down menu will say Internal or External, but will have a value of 1 or 2. Internal = 1, External = 2.

Now what I need is the drop down menu under that, pull the data from the Data Tab, and show the # column as its description.

I thought about using Data Validation, but I don't know how to make it work in this situation.

Here is a copy of the workbook... well a demo.