If you check the box to "I will control BTL File and Lang used" then you will be responsible to load the proper Language file used (*.BTL) and Language selected within the file (1-10)  You can do this thru your own procedures and store in an ini file or control file, however you wish.

BoTran uses a Global Variable for the Language Selected (G:BTLang) and Language file Selected.(G:BTFile)

You then must properly prime these two variables in the app, or each app of a multi-dll program with the proper values in the Global Embed point : Before BoTran Init

BoTran init uses these 2 variables to load the correct file and language on initializing each app in Single Exe or in multi-DLL programs.

If this is a multi-DLL then you must prime them in each app that is part of the Program.

You will need to modify the existing Language Change control, or develop your own to store the file names and language numbers you use for your control of these variables.