Mortgage Opening Balances for Existing Mortgage?

[Mark Phillips]

I want to add an existing mortgage to my GnuCash accounts. The house was
bought many years ago. I only want to start recording the values as of Jan
1, 2103, as I have the detailed bills from that date forward.

Transactions for 1/113
Assets:Home Mortgage = total unpaid principle on 1/1/13
Liabilities: Home Mortgage =  total unpaid principle on 1/1/13

How do I record the balance in the escrow account as of 1/1/13?
Assets: Escrow
how do I balance that account?

I assume I can go back to the already reconciled Jan, Feb, and March loan
payments which are recorded as

Assets:Checking = total loan payment
Expenses:Home Mortgage = total loan payment

to the following split:

Assets:Checking = total loan payment
Expense: Mortgage = mortgage Interest paid
Liabilities: Home Mortgage = principle amount paid
Assets: Escrow Account = escrow amount paid

where total loan amount = mortgage interest paid + principle amount paid +
escrow amount paid.

What will this do to my reconciliation for Jan, Feb, and March?

Thanks,

Mark