Use Excel to randomly assign teams to sports competitions

How can I get excel to resolve the following game assignment problem?

Contest Structure - before playoffs
1 2 groups with even number of teams in each group
2 minimum number of teams = 12 (no maximum)
3 number of players per team = 4
Competition Format
1 Players register in teams of 4
2 Teams are randomly assigned to a group
3 Number of pre playoff golf rounds = 6
Competition Criteria
1 Teams in Group 1 compete with teams in Group 2
2 Teams do not compete with another team more than once per season
3 Subject to 1 and 2 above, teams are randomly assigned for each round

Excel challenge
1 I want to create an excel model that will randomly assign teams to groups and pair teams for competion 6 times per season in accordance with the above criteria

2 Inputs to drive the model would include:
A Number of teams per group (must be an even number and not less than 12 teams)

B Number of rounds (curently 6 but could vary by 1 or 2 rounds at user discretion)


Output expectation
1 A grid or table that can be posted on a website showing the random team assignments for each round of golf

Sorry to drag this up from the archives but I am looking for something almost like this. Did you find anything to solve this?

Cheers