Calculating flow days help

Hello,

I got a query from Access and try to calculate the number of days at several
operation, but not sure how to go about calculating in Excel. In the query I
got the field for order#, workcenter, oper#, finishdate and other. I would
like to calculate number of work days exluding holiday at each workcenter.
sample data:

order# oper workcenter finishdate
0110 5 ABC 1/1/08
0110 10 ABC 1/3/08
0110 20 ABC 1/4/08
0110 30 ZZZ 1/6/08
0110 40 DVD 1/7/08
0110 50 DVD 1/9/08
0110 70 VHR 1/14/08

Results would like to acheive:
workcenter oper #ofdays
ABC 5, 10, 20 4 (1/1/08 to 1/4/08)
ZZZ 30 1 (1/4/08 to 1/6/08: 1/5 & 6 weekend)
DVD 40, 50 3 (1/6/08 to 1/9/08)
VHR 70 3 (1/9/08 to 1/14/08: 1/12 & 13 weekend)

Thanks so much for any help.