Make print area dynamic & replace a SUMPRODUCT with code!

Actually, thinking about it, maybe you could do something like:

dim rng, total,a,b
set rng = Sheets("Data").cells.find(Range("C1"))
do until rng is nothing  
  if Sheets("Data").Range("A" & rng.row) <Range("B1") then a = 1 else a = 0
     total = total + (a*Range("C" & rng.row))
  end if
  set rng = Sheets("Data").cells.findnext(rng)
loop
next