save nested lists on parameter server

Hy, I want to save a nested list via [setParam function (roscpp)](http://docs.ros.org/jade/api/roscpp/html/classros_1_1NodeHandle.html#a598a3b9d318d2fe9fe95f3a955a4c2fa) on the parameter server. example list: [[1,2,3],[2,6,-1]] It's easy to save a nested list via console or yaml file, but I don't know how to do it within the code via setParam ... Thanks for your help