title: Worksheet functions returning 0 when the actual value is ""
body: <p>For some time I've been aware that excel make a last minute decision to return 0 in lookup functions when the actual target value is "empty".  I know that the actual function returns the correct value because I got into the habit of using If(lookupfunction="","",lookupfunction), which is a pain but works.</p>
  
  <p>I have a table with a vlookup in a calculated column which looks up another table based on a third table with a parallel structure (using tablename[@[name]] style referencing). Some of the entries in the source table are blank and the lookup was returning blank (to my surprise and delight).  I then deleted one of the non-blank entries in the source table and the vlookup returned 0 instead of "", just for the one I deleted.  If I delete another entry, it also reverts to zero instead of "".  I checked all of the formatting and it is all set to general so the zeros are not being hidden.</p>
  
  <p>I guess that is by way of a bug report, but my question is: is there a neat way to pass "" through worksheet functions without them being converted to 0 all the time</p>