Is it possible to copy BTC balances of only some addresses while forking I want to fork a Blockchain for private use, however I want to keep only balance of some known adresses
for example if my adresses are @A(10BTC), @B(20BTC), @C(30BTC)
I want to see same adresses with same amount on the new forked one 
@A(10BTC), @B(20BTC), @C(03BTC), @D(5BTC), @E(6BTC)

Many thanks
This is possible, but will require a change to your fork's consensus rules to see the block that alters address balances as valid.

Essentially, you need to drop the utxos of addresses you don't want to have a balance on your new fork at the fork block, and leave the ones you want with a balance alone. This is of course an invalid block for regular Bitcoin clients, since utxos cannot arbitrarily disappear. You can get around this by assuming that the fork block hash is valid explicitly in your fork's code.