During Implemetation No Opening Trial Balance was Imported from QB



I work for an Ecommerce retail company that migrated from QB to Great Plains 2010.  Our ERP provider did not do the implementation correctly, and we have no opening balances in GP.  This implementation was done 3 years ago and I am trying to sort this out so we can move forward and fix our balance sheet.  We no longer have access to QB so we cannot re-import these balances into GP.  What are our options?  Should I book a GL entry of what could possibly be our trial balance from our go live.