Take a look here:
Upload Flight Plans into Garmin 430/530, G1000 with Voyager*
PocketFms* has the ability to export a FP to an SD card in the correct format to upload to a G1000 / 530 / 430 although I gather there are issues of compatability depending where the unit was sourced. There is a write up of the procdure on the forum which is straight forward. If it works this would enable FPs to be exported in either direction.
I have not tried either but would be interested to know how you get on.
* the former covers the US but PocketFMS covers just about everywhere people fly light stuff.