Can I set up a call forwarding to my own phone number abroad?

You want that a contact calls your mobile or landline number and that the call is forwarded through toolani to your phone number abroad?

Unfortunately this is not possible, unless you register all the possible "caller numbers" as your own phone numbers in your toolani account. 
If you don't do this like that, your contacts will always hear an error message when they call, saying that they are not registered.