I have a combobox on sheet 1 which i need populating with the values of cells on sheet 2.

So the combobox if possible could have the value or 2 cells in it on the same line for instance sheet 2 column 1 consists of dates and column 2 consists of times, so 1 line in the combobox would look like "22/11/2011 13:45" is that possible?
And this needs to be a continuous list but it only shows column 1 and column 2 data if column 3 is empty.