Algoritm for optimizing meetings team in competition

I need an algoritm to solve the following problem by programming in Visual
Basic.

We play a competition with this basic assumptions:
- In that competition will play N teams (e.g. 14).
- There are S sessions ( e.g. 6).
- A session counts R rounds. After each round the teams get another
opponent.
- A team will meet as many as other teams as there are rounds. this are
mostly 6 teams.
- When the number of teams for a session is odd, during each round there
is one team
that don't play and thus don't meet another team.
- Which teams will meet each other depends on the place of the teams in
the play-scheme.
For each number of teams that will participate there is a scheme.
- It is possible that one or more teams don't participate in a session.
The number of absent teams is rarely 4 or more.
- We count the frequency of the meetings between the teams.
- Before the start of a session we want the present teams place in the
scheme so that the frequenty of the meetings between the teams will
optimize.

For further explanation an example:

After 2 sessions the matrix of the meetings between the teams A to L of a
competition
with 12 teams may be:

A B C D E F G H I J K L
A - 2 0 2 1 2 2 0 1 0 1 1
B 2 1 0 1 2 0 1 0 2 1 1 1
C 0 0 0 1 1 1 0 0 1 1 0 1 (This team
has played only one session)
D 2 1 1 1 1 1 0 0 1 2 1 1
E 1 2 1 1 0 2 1 0 0 1 1 2
F 2 0 1 1 2 1 1 0 1 2 1 0
G 2 1 0 0 1 1 1 0 1 2 2 1
H 0 0 0 0 0 0 0 - 0 0 0 0 (This team
didn't play the first 2 sessions)
I 1 2 1 1 0 1 1 0 0 1 2 2
J 0 1 1 2 1 2 2 0 1 0 1 1
K 1 1 0 1 1 1 2 0 2 1 1 1
L 1 1 1 1 2 0 1 0 2 1 1 1

When a team cannot play a round, because the number of teams for a session
is odd,
we see in the matrix a meeting with the team itself. See for example the 1
in the element (B, B).

Suppose that all 12 teams will be present during session 3. The play-scheme
for 12 teams is:

Team number meet the teams
1 2, 4, 5, 7, 11, 12
2 1, 3, 5, 7, 9, 11
3 2, 4, 6, 8, 10, 12
4 1, 3, 5, 7, 9,10
5 1, 2, 4, 6, 8, 12
6 3, 5, 7, 9, 10, 11
7 1, 2, 4, 6, 8, 12
8 3, 5, 7, 9, 10, 11
9 2, 4, 6, 8, 10, 12
10 3, 4, 6, 8, 9, 11
11 1, 2, 6, 8, 10, 12
12 1, 3, 5, 7, 9, 11

Which teamnumbers must we attribute to the teams A to L to optimize the
meetings between
the teams? An attribution is for example:
A gets number 3/ B to 5/ C to 1/ D to 12/ .... etc.

Has anyone a solution for this optimize-problem? May be based on experience
with this kind of competitions.
I am very interested.

Jan van der Meulen