Thanks for reaching out to the Community, woofterm.
I can provide information about managing foreign currency accounts.
In your case, in order to make a deposit for other amount, you'll just have to change the currency.
To know more about multicurrency, you can check this article: Set up and use Multicurrency.
For additional information, you might find this article helpful: Deposit customer payments.
If you have any other questions about this, please don't hesitate to leave a comment below. I'd be glad to further help.