Hello,
Try:
<TABLE style="WIDTH: 323pt; BORDER-COLLAPSE: collapse" border=0 cellSpacing=0 cellPadding=0 width=430><COLGROUP><COL style="WIDTH: 323pt; mso-width-source: userset; mso-width-alt: 7862" width=430><TBODY><TR style="HEIGHT: 15pt" height=20><TD style="BORDER-BOTTOM: #f0f0f0; BORDER-LEFT: #f0f0f0; BACKGROUND-COLOR: #d7e4bc; WIDTH: 323pt; HEIGHT: 15pt; BORDER-TOP: #f0f0f0; BORDER-RIGHT: #f0f0f0" class=xl63 height=20 width=430>=IF(AND(COUNTIF(C:C,">=30%"),C21>2000),C21-100)
</TD></TR></TBODY></TABLE>
Using Excel 2007
Edit: I see the changes to OP, The above is incorrect.
-Jeff