how to get an array from a number string

I need to extract single elements from a code such 4 digit in a six digit code which is expressed as a string.

Answer 1

[Star Strider]

This works:

nstr = '123456';
first_four = nstr(1:4)

first_four =
1234

EDIT — If you want it as a number instead of a string, then use str2num or str2double.