Suppress Group Conditionally

Hi,
I have a group that shows 4 fields. One of the fields is a date field. I would like to suppress the group if the date field is greater than 1/1/2007. Anyone know how I can go about doing this? I have read about conditional formatting but I am not sure where to go to do all this.
Thanks!

I figured this out but ran into another problem. Is there a way to suppress a group based on whether or not another group is suppressed? For instance, if group 1 supresses, I would like for group 2 to suppress.