pattrstorage/bpatcher/matrixctrl

Hello,

I try to send the message "interp matrixctrl off" to a matrix(name
matrixctrl) in a bpatcher with no success. When I send the same message
to a matrix (name: matrixctrl2) in the main patch it works, the
clientwindow report the change, interp goes off. I need to send this
message because the matrix do not keep the preset during the
interpolation (from 1. to 2.) if it's not off, so the matrix inside my
mainpatch do what it's need but not the one in the bpatch which is the
one i need to do it in my project. See an exemple of the dilema below.
I must miss something obvious but don't get it even going throug manuel
>pattr>hubpattr>autopattr

thanks in advance for any lights
Franck