MetaTrader 4 Multiple Accounts and Multiple Signals

 
If I were to set up 4 accounts with my broker, and subscribe to a different signal for each account, can I use just one instance of the MetaTrader 4 software to duplicate trades from each signal, or do you have to be "logged in" to the account that you want trading?
 
You can only log into one account with a terminal and can only trade with that one.
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