Foreign Currency Translation Ledger entries

Hello:

We are a Canadian company and our functional currency is Canadian. We do have the USD set up as a separate currency.

When we post a USD ledger entry it is converted into Cdn$ using the currency rate in effect in the Data Maintenance for Currency Rate table.

However for individual transactions that rate is not always equal to the actual foreign exchange rate being charged by a credit card company or a bank.

Is there a way within the ledger entry for these types of transactions to alter the Cdn $ converted values (ie over-right what is being recorded based on the USD entry multiplied by the rate in the currency table)?

For example - Lets say I do a simple bank transfer between my Canadian and USD Bank accounts,. Where I buy $100 USD. Lets say the bank charges me $145 Cdn. The Fx rate charged by the bank is $1.45 However lets say for example that the rate in the data maintenance for currency rate table is $1.40. When I record the USD entry (Ie Dr US Bank, Cr Cdn Bank $100 USD), Cetec is going to record that entry in Cdn (Dr US Bank $140.00, Cr Cdn Bank $140). Is there anyway, other than a separate Journal entry, to change the Cdn $ entry to reflect the true conversion rate (ie Dr US Bank $145, Cr Cdn Bank $145)

Thank you!!