Appointment Scheduler - multiple

Have a challenge here and was hoping MS Excel could help in some form or fashion.

I am trying to schedule meetings for businesses within a one or two day time period.
Lets say i have 20 businesses in Group A and 100 businesses in group B. Meetings will not occur between businesses in the same group. Some of the businesses in group A will not meet with some of business in Group B. They are selective meetings. So far i made a simple spreadsheet with Group A listed in Columns and Group B in rows. I then went through and placed a 1 in the interesting cell if the two businesses need to meet. So i have all the meetings i want to take place and who they are to take place between mapped out. Now comes the hard part of scheduling the times. Obviously a business cant be in two meetings at once. What do you suggest i do? SHould i just do it by hand....this can be very time consuming especially if there are cancelation. Or is there a function in excel that will help me. each meeting is 45 minutes long, and i am planing to have them on one day with a runover happening on day 2 (or 3 as needed)

Suggetsions!

martin

thanks for your response.

so each of the 20 businesses in Group A has a meeting location. That means that they can each conduct a meeting at the same time. My scheduling revolves around making sure they are not meeting with the same person at the same time. In addition trying to make the meetings for each business be in a row.

What do you suggest. I am new to this depth of excel. Ultimatly i am trying to devise something that will easily allow me to set the schedules, but more importantly, if there is a cancellation, or if a business in Group A requests a meeting with a business not on their schedule I would now the times available for that busines.

Many thanks.
c