Hi there,
First of all, I assume that given Excel only goes up to column 'IV' that the column headings don't have every date on it... That would then mean that you can't do this in the way you are thinking...
This would therefore be the really simple way of doing it...
Try reversing the columns/rows and then try this...
In cell A2 type the first date of the holiday year. (e.g., 01/01/2008)
Then in cell A3 type the following formula:
"=IF(WEEKDAY(A2+1)=6,A2+3,A2+1)"
If your company works 6 days a week instead of 5 then replace the 6 with a 7 and the A2+3 with A2+2.
Then copy and paste this formula across all rows until all possible holiday dates are shown.
Then type the names of people in the columns.
Select cell B2 and click Window->Freeze Panes
Then click Format->Conditional Formatting
Change Condition 1 to 'Formula is' and then type =B2=1 in the box. Set the format to have a different background colour such as yellow which will make the booking stand out. Then copy and paste this cell to all possible ranges of the holiday table...
Then if a person books a day off as holiday then enter a '1' in that persons name/date cell.
Once you have done this then highlight all the cells from A1 down to the end of the date list and click Data->Filter->Autofilter.
Once you have done this you can then use the 'Autofilter' to select a date or range of dates to display the holidays for...
Example: Choose [custom] from the drop down menu and then the first condition is 'greater than or equal to' and type 01/01/2008 and the second condition is 'less than' and type 01/02/2008 then click 'OK'. You will now see all the holiday bookings for January 2008!
Of course there are far more intricate ways of doing this that are far less crude (using Visual Basic programming for applications) but they couldn't be explained here on Y!A in simple detail...
Perhaps you could try the Microsoft Office sample files (templates) to see if there is something suitable that you can adapt instead:
http://office.microsoft.com/en-gb/templates/CT101527321033.aspx?av=ZXL
Good luck!