Excel 2007 : Formula to workout target dates

Hi guys,

I'd like some help with formulas on excel 97 as I'm not very good with them.

We have a spreadsheet at work with the following 4 targets:

9 week target date - Cell D1
15 day target day - Cell R1
10 day target date - Cell Y1
20 day target date - AE1

Now what I need is a formula to workout each target from a date I enter in cell B1. Here's the tricky bit, I also want excel to exclude all weekends and holidays.

Any ideas?

Thank you

Steve