I use find/replace for simple formulas but in the following example find/replace gets to be a lot of work.
<TABLE style="WIDTH: 60pt; BORDER-COLLAPSE: collapse" border=0 cellSpacing=0 cellPadding=0 width=80 x:str><COLGROUP><COL style="WIDTH: 60pt; mso-width-source: userset; mso-width-alt: 2925" width=80><TBODY><TR style="HEIGHT: 12.75pt" height=17><TD style="BORDER-BOTTOM: windowtext 0.5pt solid; BORDER-LEFT: windowtext 0.5pt solid; BACKGROUND-COLOR: transparent; HEIGHT: 12.75pt; COLOR: red; BORDER-TOP: windowtext 0.5pt solid; BORDER-RIGHT: windowtext 0.5pt solid; mso-ignore: style" class=xl41 height=17 width=80 align=right x:num="-2.6975149957155099E-2"></TD></TR></TBODY></TABLE>
IF($C6=0,"",(SUM(C6:N6)-SUM(O6:Z6))/SUM(O6:Z6))