Excel 2007 : Automatically select the next cell once a data validation menu option has been selected

I have a conditional data validation menu, which is several layers deep. I've attached a much simplified version to demonstrate what I'd like to achieve.

When the user selects an option from the data validation list in B4, I'd like for cell B5 to automatically be 'selected' and showing the data validation dropdown arrow, rather than the user having to click cell B5 to first highlight it.

My actual sheet has seven conditional cells and it is a pain having to click the next cell in the chain each time and then click the drop down arrow. It would be neat if the user could select an option from the first cell, then simply click the arrow and select an option from the next cell and so on.

Is this possible to do either with or without VBA and if so, how?

Anyone have any ideas as to how to do this or if it is even possible?