Read string(text) data in field with Matlab Analysis | MATLAB IoT Analytics | Forum

Hi,
I have a field that have string/text data like this:
field1 : "120_60_30_40"

What i want to ask is, how we can extract/read that data using Matlab Analysis. So i can get individual data integer (in array perhaps) like this:
num(0) = 120
num(1) = 60
num(2) = 30
num(3) = 40

Thanks