If the radio in your car is the original factory installed model; the codes would normally be available from a dealership. They also are listed in the documentation given to the original owner at purchase. If your car has an original factory installed radio, and you do not have these documents; contact
If your radio is an aftermarket item; contact the shop which installed it; or a shop which installs and services that brand of radio.
Here's a list posted on this site by cdclassics last year:
Daewoo Radio Codes
Here is a list of the most common codes it should be one of these..
5436 <<< 01 Leganza Code