If I understand what you're asking...
You have a lookup table something like this...
Sheet1
<TABLE style="BACKGROUND-COLOR: #ffffff; PADDING-LEFT: 2pt; PADDING-RIGHT: 2pt; FONT-FAMILY: Verdana,Arial; FONT-SIZE: 10pt" border=0 cellSpacing=0 cellPadding=0><COLGROUP><COL style="WIDTH: 30px; FONT-WEIGHT: bold"><COL style="WIDTH: 72px"><COL style="WIDTH: 72px"></COLGROUP><TBODY><TR style="TEXT-ALIGN: center; BACKGROUND-COLOR: #cacaca; FONT-SIZE: 8pt; FONT-WEIGHT: bold"><TD></TD><TD>E</TD><TD>F</TD></TR><TR style="HEIGHT: 17px"><TD style="TEXT-ALIGN: center; BACKGROUND-COLOR: #cacaca; FONT-SIZE: 8pt">1</TD><TD style="BORDER-BOTTOM: #000000 1px solid; TEXT-ALIGN: center; BORDER-LEFT: #000000 1px solid; BORDER-TOP: #000000 1px solid; BORDER-RIGHT: #000000 1px solid">1</TD><TD style="BORDER-BOTTOM: #000000 1px solid; TEXT-ALIGN: center; BORDER-LEFT-COLOR: #000000; BORDER-TOP: #000000 1px solid; BORDER-LEFT-WIDTH: 1px; BORDER-RIGHT: #000000 1px solid">22</TD></TR><TR style="HEIGHT: 17px"><TD style="TEXT-ALIGN: center; BACKGROUND-COLOR: #cacaca; FONT-SIZE: 8pt">2</TD><TD style="BORDER-BOTTOM: #000000 1px solid; TEXT-ALIGN: center; BORDER-LEFT: #000000 1px solid; BORDER-TOP-COLOR: #000000; BORDER-TOP-WIDTH: 1px; BORDER-RIGHT: #000000 1px solid">2</TD><TD style="BORDER-BOTTOM: #000000 1px solid; TEXT-ALIGN: center; BORDER-TOP-COLOR: #000000; BORDER-TOP-WIDTH: 1px; BORDER-LEFT-COLOR: #000000; BORDER-LEFT-WIDTH: 1px; BORDER-RIGHT: #000000 1px solid">0</TD></TR><TR style="HEIGHT: 17px"><TD style="TEXT-ALIGN: center; BACKGROUND-COLOR: #cacaca; FONT-SIZE: 8pt">3</TD><TD style="BORDER-BOTTOM: #000000 1px solid; TEXT-ALIGN: center; BORDER-LEFT: #000000 1px solid; BORDER-TOP-COLOR: #000000; BORDER-TOP-WIDTH: 1px; BORDER-RIGHT: #000000 1px solid">3</TD><TD style="BORDER-BOTTOM: #000000 1px solid; TEXT-ALIGN: center; BORDER-TOP-COLOR: #000000; BORDER-TOP-WIDTH: 1px; BORDER-LEFT-COLOR: #000000; BORDER-LEFT-WIDTH: 1px; BORDER-RIGHT: #000000 1px solid">22</TD></TR><TR style="HEIGHT: 17px"><TD style="TEXT-ALIGN: center; BACKGROUND-COLOR: #cacaca; FONT-SIZE: 8pt">4</TD><TD style="BORDER-BOTTOM: #000000 1px solid; TEXT-ALIGN: center; BORDER-LEFT: #000000 1px solid; BORDER-TOP-COLOR: #000000; BORDER-TOP-WIDTH: 1px; BORDER-RIGHT: #000000 1px solid">4</TD><TD style="BORDER-BOTTOM: #000000 1px solid; TEXT-ALIGN: center; BORDER-TOP-COLOR: #000000; BORDER-TOP-WIDTH: 1px; BORDER-LEFT-COLOR: #000000; BORDER-LEFT-WIDTH: 1px; BORDER-RIGHT: #000000 1px solid">97</TD></TR><TR style="HEIGHT: 17px"><TD style="TEXT-ALIGN: center; BACKGROUND-COLOR: #cacaca; FONT-SIZE: 8pt">5</TD><TD style="BORDER-BOTTOM: #000000 1px solid; TEXT-ALIGN: center; BORDER-LEFT: #000000 1px solid; BORDER-TOP-COLOR: #000000; BORDER-TOP-WIDTH: 1px; BORDER-RIGHT: #000000 1px solid">5</TD><TD style="BORDER-BOTTOM: #000000 1px solid; TEXT-ALIGN: center; BORDER-TOP-COLOR: #000000; BORDER-TOP-WIDTH: 1px; BORDER-LEFT-COLOR: #000000; BORDER-LEFT-WIDTH: 1px; BORDER-RIGHT: #000000 1px solid">85</TD></TR><TR style="HEIGHT: 17px"><TD style="TEXT-ALIGN: center; BACKGROUND-COLOR: #cacaca; FONT-SIZE: 8pt">6</TD><TD style="BORDER-BOTTOM: #000000 1px solid; TEXT-ALIGN: center; BORDER-LEFT: #000000 1px solid; BORDER-TOP-COLOR: #000000; BORDER-TOP-WIDTH: 1px; COLOR: #ffffff; BORDER-RIGHT: #000000 1px solid">_</TD><TD style="BORDER-BOTTOM: #000000 1px solid; TEXT-ALIGN: center; BORDER-TOP-COLOR: #000000; BORDER-TOP-WIDTH: 1px; BORDER-LEFT-COLOR: #000000; BORDER-LEFT-WIDTH: 1px; BORDER-RIGHT: #000000 1px solid">55</TD></TR></TBODY></TABLE>
And you have a lookup formula something like this...
VLOOKUP(A1,E1:F6,2,0)
However, if cell A1 (the lookup value) is empty instead of the #N/A error you want the result from cell F6 of the lookup table.
Is this what you want?
If so, then a formula like this:
=IF(A1="",F6,VLOOKUP(A1,E1:F6,2,0))