I know of several approaches using a macro (VBA) to show/hide columns and rows in Excel, but I cannot figure out or find a way to do this using either a formula or conditional formatting. Of particular interest is Excel 2007 - but I'd be curious to know if someone has managed to do it in any version of Excel.

For those who want background, I have a spread of data with dates across the top and labels down the first column. I would like to specify a date window (on another sheet) as two cells with drop down dates (months) which would then show/hide the appropriate columns on the data sheet.