Try:
Code:
Public Function Minus(rng As Range)
Minus = (2 * rng.Cells(1)) - Application.Sum(rng)
End Function
Excel 2003<TABLE style="BORDER-BOTTOM: #a6aab6 1px solid; BORDER-LEFT: #a6aab6 1px solid; BACKGROUND-COLOR: #ffffff; BORDER-COLLAPSE: collapse; BORDER-TOP: #a6aab6 1px solid; BORDER-RIGHT: #a6aab6 1px solid" rules=all cellPadding=2><COLGROUP><COL style="BACKGROUND-COLOR: #e0e0f0" width=25><COL><COL><COL></COLGROUP><THEAD><TR style="TEXT-ALIGN: center; BACKGROUND-COLOR: #e0e0f0; COLOR: #161120"><TH></TH><TH>A</TH><TH>B</TH><TH>C</TH></TR></THEAD><TBODY><TR><TD style="TEXT-ALIGN: center; COLOR: #161120">1</TD><TD style="TEXT-ALIGN: right; FONT-WEIGHT: bold">1</TD><TD style="TEXT-ALIGN: right"></TD><TD style="TEXT-ALIGN: right">-4</TD></TR><TR><TD style="TEXT-ALIGN: center; COLOR: #161120">2</TD><TD style="TEXT-ALIGN: right">2</TD><TD style="TEXT-ALIGN: right"></TD><TD style="TEXT-ALIGN: right"></TD></TR><TR><TD style="TEXT-ALIGN: center; COLOR: #161120">3</TD><TD style="TEXT-ALIGN: right">3</TD><TD style="TEXT-ALIGN: right"></TD><TD style="TEXT-ALIGN: right"></TD></TR></TBODY></TABLE><TABLE style="BORDER-BOTTOM: #a6aab6 1px solid; BORDER-LEFT: #a6aab6 1px solid; BACKGROUND-COLOR: #ffffff; BORDER-COLLAPSE: collapse; BORDER-TOP: #a6aab6 1px solid; BORDER-RIGHT: #a6aab6 1px solid" rules=all cellPadding=2><THEAD><TR style="TEXT-ALIGN: center; BACKGROUND-COLOR: #e0e0f0; COLOR: #161120"><TH>
Sheet1</TH></TR></TD></THEAD><TBODY></TBODY></TABLE>
<TABLE style="BORDER-BOTTOM: black 2px solid; BORDER-LEFT: black 2px solid; PADDING-BOTTOM: 0.4em; BACKGROUND-COLOR: #ffffff; PADDING-LEFT: 0.4em; PADDING-RIGHT: 0.4em; BORDER-COLLAPSE: collapse; BORDER-TOP: black 2px solid; BORDER-RIGHT: black 2px solid; PADDING-TOP: 0.4em" rules=all cellPadding=2 width="85%"><TBODY><TR><TD style="PADDING-BOTTOM: 6px; PADDING-LEFT: 6px; PADDING-RIGHT: 6px; PADDING-TOP: 6px">
Worksheet Formulas<TABLE style="BORDER-BOTTOM: #a6aab6 1px solid; TEXT-ALIGN: center; BORDER-LEFT: #a6aab6 1px solid; BACKGROUND-COLOR: #ffffff; BORDER-COLLAPSE: collapse; BORDER-TOP: #a6aab6 1px solid; BORDER-RIGHT: #a6aab6 1px solid" rules=all cellPadding=2 width="100%"><THEAD><TR style="BACKGROUND-COLOR: #e0e0f0; COLOR: #161120"><TH width=10>Cell</TH><TH style="TEXT-ALIGN: left; PADDING-LEFT: 5px">Formula</TH></TR></THEAD><TBODY><TR><TH style="BACKGROUND-COLOR: #e0e0f0; COLOR: #161120" width=10>C1</TH><TD style="TEXT-ALIGN: left">=minus(
A1:A3)</TD></TR></TBODY></TABLE></TD></TR></TBODY></TABLE>