I beleive I found the area for you to look to solve conditional formatting. In the help file, look under USing Report Events. However, this is very new to me.
For example, you can use the ItemDataBound event of a DetailSection to color alternate rows on a report:
private void detail_ItemDataBound(object sender, System.EventArgs e)
Processing.DetailSection section = sender as Processing.DetailSection;
if (i % 2 == 0)
section.Style.BackgroundColor = Color.PowderBlue;