Need complex formula for Volleyball league

[Rok88]

We have a volleyball league and we are looking for scheduling formula that can accommodate our leagues format:
Number of teams varies from year to year: 12 this year
Number of courts varies from year to year: 4 this year (teams/3 and rounded up)
Number of weeks varies from year to year: 20 this year
3 teams per court
3 time slots per court

• Each team play 2 games and Minor Officiates (MO) 1 game

Need to divide games as evenly as possible and distribute 'officiating' slot evenly (ideally team 1 would have an even spread of officiating for all three time slots in a season).

[TABLE="width: 500"]
<tbody>[TR]
[TD]Court 1[/TD]
[TD]MO[/TD]
[TD]Court 2[/TD]
[TD]MO[/TD]
[TD]Court 3[/TD]
[TD]MO[/TD]
[TD]Court 4[/TD]
[TD]MO[/TD]
[/TR]
[TR]
[TD]1 vs 5[/TD]
[TD]9[/TD]
[TD]2 vs 6[/TD]
[TD]10[/TD]
[TD]3 vs 7[/TD]
[TD]11[/TD]
[TD]4 vs 8[/TD]
[TD]12[/TD]
[/TR]
[TR]
[TD]1 vs 9[/TD]
[TD]5[/TD]
[TD]2 vs 10[/TD]
[TD]6[/TD]
[TD]3 vs 11[/TD]
[TD]7[/TD]
[TD]4 vs 12[/TD]
[TD]8[/TD]
[/TR]
[TR]
[TD]5 vs 9[/TD]
[TD]1[/TD]
[TD]6 vs 10[/TD]
[TD]2[/TD]
[TD]7 vs 11[/TD]
[TD]3[/TD]
[TD]8 vs 12[/TD]
[TD]4[/TD]
[/TR]
</tbody>[/TABLE]