There are no combo codes in any Sony remote. You will have to learn everything from the original remote.

The 3000 should not have a problem learning from the original remote.

Here's a bunch of stuff that might help you out.

RM-AV3000/3100 NEWCOMERS PACKAGE-WELCOME-CHECK THESE OUT (IF YOU HAVEN'T ALREADY DONE SO) AND SAVE YOURSELF SOME PROBLEMS

SYSTEM CONTROL KEYS: Everything you need to know about them

HOW TO LABEL, CHANGE OR HIDE BUTTONS

CHANGING BATTERIES (May not be necessary on RM-AV3100, but why take a chance when it's only 20 seconds?)

AND IF YOU HAVE A SONY RECEIVER:
HOW TO CHANGE YOUR RECEIVER AND REMOTE TO AV1 (or AV2) COMMAND MODE

AND HERE IS SOME MORE INFO IN CASE THE MANUAL GETS TOO CONFUSING

REMOTE CENTRAL RM-AV3000/RM-AV3100 FORUM REVIEW (INCLUDING THE QUICK PROGRAMMING GUIDE)

Also, check out the TIPS AND TRICKS section.