You can set up a new security with a zero basis by recording a purchase of the security for $0, then re-valuing the security to market value. This will create an UGL entry for the difference between the two amounts. You will also have an audit trail of this spin-off acquisition.

With regards to your second example, please see the topic: Stock spin off for more information.
1. You will be selling zero shares of your original stock for the amount of the spin-off. This will lower the basis of your original stock but your number of shares remains the same.

2. Next, you will purchase the new security for the amount of the spin-off that you recorded in the first transaction. The net of these two transactions will be $0 and therefore will not affect your cash balance.

Note, you can search the user forums to find answers to your questions that have already been posted by other users. Just click on the Search link near the top right corner of any user forum page to find topics with matching keywords that you are interested in.