I am trying to combine tow A/R into one.

here is the scenario: A/R account has an account left over from last year. So when I tried to add to it it didn't allow me, the account didn't show up as it is a control account. Than I changed it to A/R general account. Now all my entries are going automatically into that account. I would like to know how I can get the amount sitting in the A/R account to the A/R general. 

I tried a general journal entry but failed as A/R is a control account and does not show up in the list to choose Accounts from. 

Any help is greatly appreciated. 

Thank you.

Carmen