I bought it as part of a bundle, which has no serial number in my list. How do I organise to get one, please?

bundle? in any case, register it and the info will be in your account

If you do not see a line item in your store account for "SONAR X1 Expanded" then you will need to contact customer support.

I bought it as part of the "First-Class upgrade to Production Suite"

Cakewalk Total Expanded Holiday Bundle (Download). AFAICS I can't register wop a serial number...

"If you do not see a line item for "SONAR X1 Expanded" then you will need to contact customer support. " Ah. OK. Thanks. Will do.

Go to cakewalk.store.com, logon to your account and you should see the registration code. 

because it's part of a bundle, it does not show

In my case "SONAR X1 Producer", "SONAR X1 Expanded", "ZETA+ 2.1" and the "ProChannel Module - PC4K S-Type Expander Gate" make up the "First-Class upgrade to Production Suite", the bundle that I purchased. Each one of those have separate line items in my store account, all with their own registration info. If you are missing registration information for parts of the bundle you purchased, it will need to be addresses by customer support.

12/26/2011-Cakewalk Total Expanded Holiday Bundle -(Download)...is all I get: two columns blank. No other listings of the items in the bundle. I have emailed support.