I guess I don't fully follow the question, but it is too late set the language in the flow it needs to be set upon launch via the query string. For example, surveylink/?Q_Language=DA.

Yeah that's what I'm trying to solve. How can i get it to work if the string reads only "Lang" ? Can't i set that up in the survey flow?
Feels like I should be able to say: '"Lang" means "Q_Language" so treat it as such.'

Nope, it's too late if you are trying to change it in the survey logic. It needs to past via the url as Q_Language. What you are asking needs be done before you launch the survey url.

I have the same problem: the software that I'm using for the conjoint part (sawtooth) does not allow pass-in fields with "_". So I cannot use "Q_language" as variable in the survey link. But I need to get respondents redirected to Qualtrics and based on the variable, the respective survey language should be displayed.
Is there a way to adapt the "Q_language" variable in qualtrics, e.g. to "Qlanguage" or is it a fixed name?
Other options would be I program different surveys for each language and have different survey links, but would prefer the first option.
Thanks! Laura

https://community.qualtrics.com/XMcommunity/discussion/comment/42975#Comment_42975I have gotten some success with just using "Language".

https://community.qualtrics.com/XMcommunity/discussion/comment/43177#Comment_43177Thank you, good to know! In my case I could successfully "overwrite" the language variable in the redirect link from Sawtooth back to Qualtrics - for everyone with the same problem I used: &Q_Language=[%Value(lang)%]