message to set matrixctrl grid

Hello,

I often use the Matrixctrl object
and each time I said to myself
"it could be nice if a simple message could set the
grid of this"
specially when the matrix has 45 in for 37 out
we have to count 0, 1, 2, 3 etc...
the eyes have a cast ...and if somebody speak to you
during that, you can start again ....well !!!

I don't see any messages who can do this

Do you know something ?

many thanks

Eryck