If statement to include working days, exclude holidays

For the fomula in I68 I want to change it to say IF(H66-H57< 252 Workdays excluding holidays. How can this be done to count workdays instead of just a straight day count?

if you name your holiday list of dates, holidays (through, Insert|Name|Define)

then you can use:

=IF(NETWORKDAYS(H57,H66,holidays)<252,HLOOKUP(G66,$G$56:$K$57,2,),I66)