Help With Merging Old Accounts

I will try to make this sound simple.
I have an old account and a new account.
On the old account, there is a character I want to transfer over to my current account.
This old account was made before the time when you had to have it be a Battle.net account, in other words, your login name could be anything you wanted it to be instead of an email address.
I tried to transfer this character but was unable to because it was not a Battle.net account.
I understand that I can merge this old account into my current one aka, the Battl.net account.
But the question is, when and if I merge this account, will I be able to transfer this character?