Hi! My goal is to find out how many questions were asked that received non-null responses before a particular question of interest. This will vary by each submission in my survey since different respondents will give null responses to different questions/skip different questions. In order to do this, I have a name of a variable stored as a local as well as a unique ID for each submission stored as a local. I want to go into another dataset, narrow down the dataset by querying using unique ID for each submission, further narrow down the dataset by removing columns that have null responses, and find out where in the order of all the variables that have non-null responses this particular variable lies. This means I need to be able to loop through the column names themselves as opposed to the content of the columns. How do I do that? Thank you very much for your help!