Hi swisspm,
If you are entering these transactions manually, you can use this option in the Buy/Sell dialog:
Use Cash Account
When recording a buy or sell transaction the corresponding cash will be entered into your default cash account. In the case where the investment is not in the default currency and you have multiple cash type investments of differing currencies in the same sub-portfolio as the investment, you will be given the choice of which cash investment to use. Otherwise, your specified default cash account will be used.
This will be a drop-down list of available Cash investments you can use for this transaction.
You'll only see this option if you have multiple "cash" type investments and they aren't all in the same currency.
Also, you can organize your investments into sub-portfolios by currency, and assign a different cash account for each currency. In this case the correct default cash account is used without you having to pick it. If you're retrieving transactions this may be better. See the option "Put Investments of Non-Default Currency in Separate Sub-Portfolios" in the
New Investments Options Dialog.