how to copy terms from one language to another in MultiTerm

Hello!

I have just created a termbase in Multiterm. It contains terms in 3 languages, say: LangA, LangB, LangC. I have 100% coverage for both LangA and LangC, but only 10% for LangB. Now I need to translate a document from LangB to LangC in the Studio and I want this termbase to help me. Terms which do not exist in LangB in the base are simply the same as in LangA, so I would like to do one of the following:

1) in the MutliTerm copy terms from LangA to LangB for those entries, where term for LangB is not present

OR

2) force Studio to search for terms in LangA when LangB is not present, while translating from LangB to LangC.

Is it possible to do any of above? I expect 1 is more likely - after all it is a simple database task.

I think the problem is quite general and that is why I tried to keep the question at the general level. In my case it is a database of Polish language exonyms for Italian endonyms. The thing is I'm translating from English into Polish;  the English language text simply uses Italian endonyms while the Polish must contain Polish exonyms.

I expect I could export the termbase, change outside Multiterm / Studio and import back but it does not seem to be the best solution.

Sorry, I'm a new Studio / MultiTerm user and new at the forum. If similar question was answered elsewhere, please just let me know the link. Thank you!