ordinal regression with MCMCglmm

Hi,
I am trying to figure out how to fit an ordinal regression model with
MCMCglmm. The "MCMCglmm Course notes" has a section on multinomial
models but no example of ordinal models. Suppose I have the following
data

 > data
   resp treat group
1     4     A    1
2     4     A    1
3     3     A    2
4     4     A    2
5     2     A    3
6     4     A    3
7     2     A    4
8     2     A    4
9     3     A    5
10    2     A    5
11    1     B    6
12    1     B    6
13    1     B    7
14    2     B    7
15    2     B    8
16    3     B    8
17    2     B    9
18    1     B    9
19    2     B   10
20    2     B   10

and the "resp" is an ordinal response, "treat" is a treatment and
"group" is membership to a group. Assume I would like to fit an ordinal
model between "resp" and "treat" by having "group" effects as random
effects. How would I specify such a model in MCMCglmm? And how would I
specify the prior distributions?

All help is greatly appreciated.

regards, Kari