The formula below works well, but I would like to add 2 modifications.

={MEDIAN(IF((Worksheet!C3:C1968=Aggregate!A5)*(Wor ksheet!H3:H19680),Worksheet!H3:H1968,""))}

1. IF the value is blank how do I modify so it leaves the cell blank
instead of the famous, "#num!" error

2. I would like to add a date range, ie. 2005-2008, to the conditions. The
current format of the date is, "04-mar-01. This doesn't seem to work.
Iadded this to the above
*(Worksheet!G3:G1968=2005)*(Worksheet!G3:G1968<=2 008)...

Thanks.