TConditionalFormatRule.Priority Property
Priority for the rule. 1 means the highest priority and higher number mean that the rule will be evaluated later. Note that priorities of all conditional rules must be unique on the sheet. If you specify a duplicated priority, all other priorities might be shifted when you save the file so they keep being unique.
Syntax
Namespace: FlexCel.Core
public Int32 Priority { get; set; }