Over Type Values To Create New Record?

I'm looking to record bets and winnings for multiple accounts with a running balance for each account and a running grand total. On the face of it a spreadsheet seemed to be the answer but I need to create a history of bets placed and winnings received. The friend, for whom I'm doing this, wants to be able to overtype current values to create new records. There must also be a facility to create new accounts.

Account A has an opening balance of £135.00 and the other accounts each have their own balances.

A bet of £100 is placed against Account A i.e. a debit, so the balance is now £35.00. Subsequently, a win of £150.00 is received of £150 so the balance is now £185.

Each bet should, I think, have an effective date and an inactive date. Current records will have an effective date but the inactive date will be null. Completed bets will have both an effective date and an inactive date.

Wins only need a date created date.I need to display the account name, current bet, winning amount and balance on the same row - using a form? When the form is opened there will be a column of account names, a column of current bets, a column of winnings and a column of balances.

If there is a current bet then that value should be shown in the appropriate text box. When a win is received the user should type that value in the 'Win' text box and a new Win record should be created with today's date. The inactive date of the current bet should be updated to today's date.

Now the Current_Bet text box should be empty as should the Winning text box.

The user should now be able to enter a new value in the Current_Bet box and create a new current bet record with an effective date of today and a null inactive date.

How can I populate the Current_Bet box with the value of the current record, make the changes described above and use the same text box to enter new values and create new records.

Essentially the form would look pretty much a spreadsheet where the user can just overtype values but a history of changes has to be recorded and the balance isn't just the sum of the displayed values because if it was then each time values were overtyped the balance would change and would take no account of the history.