Selecting date in drop down list

[Joe123]

Hi

I have a list of dates in a drop down list I created using data validation. I want to write a macro that selects the date in the list below the date currently selected. For example if Jan -11 is selected I want the macro to go in and select Feb-11. I know how to record a macro to do this once but how do I keep moving down the list of dates each time I run the macro?

Anyone know how to do this? I'm a VBA rookie

Thanks