Quite easy.

Wouldn't that be better to do with CC from one single adress?
Sure, but not with CC as it can not be easily automated. The best way I can think of is setting an account for the address you want to send from (in yacoin-qt debug window console for example):
setaccount
Give it some nice account name.

Then instead of "sendtoaddress" use "sendfrom" (replace fromaccount by the name of the newly created account):
sendfrom