Is it possible to load total of transactions as Balance in RC?

Summary:

My client is using Balance Comparison with TM. They are loading transactions in TM from one of the source but that source does not hold balances so client wants to total up the transactions and show that as a closing balance. Is it possible to do that somehow in Data management or by any other way?

Content (required):

They are pulling one side of balance from GL but other source has only transaction and no balance.

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