the Query language is undocumented, at least in the help. I think I saw a BNF definition at some point somewhere, but it was that of English version.
In German version of TurboCad it's translated and the Query "ALL" working in English version doesn't help, you have to use the German word "ALLE". More to it, although you go over API, on failure you get user dialogs from TurboCad (at least two), which the user has to manually close, before you get back to your code.
I tried to find in the API some way how to get the language of the TurboCad, but wasn't successful, Application.Version, Application.Build, Application.Properties ... nothing helped. I don't know what is Application.Environment, I couldn't iterate it (I didn't try VB6 when thinking of it now). Closest were Application.Properties, there are multiple language relevant strings, but they all are user definable, so it's imprecise to use.
Unfortunately, my project is already over it's deadline and we ended up in not supporting other languages.
Wish you all happy development and if anybody would have an answer, post it in.