Hi,
we recently released our tool for half-automatic migration of LON-CAPA problems to Moodle STACK.
You can find it here: https://github.com/kiliandangendorf/lc2mdl
Feel free to use it.
We also support multilingual question. If you need other languages than German or English, some short-intertexts have to be changed. Please contact us, if necessary.
best regards
Frauke