How can you distinguish between 'no response' and 'not applicable' on slider scale?

Hi,
In short, I need to be able to distinguish 'not applicable' from 'no response' on a slider scale. This is the same question posted by cjenkins but the responses don't seem to answer it.
Of note, I have already collected my data so cannot change the way the questions were formatted.
I have a slider where participants rate the importance of a variable from 0-100, or they could check a 'Not applicable' box (which I renamed 'Unable to respond'). If they opted not to move the slider, this was taken to mean 0 (i.e. the variable is of 0 importance out of 100).
The study team realised we needed to distinguish between someone intentionally not moving the slider (i.e. leaving it on 0 saying the variable isn't important) from people who just skipped the question. As such, at the end of each question we had a checkbox saying: "When we analyse the survey results, we will need to be able to distinguish between missing data or 'unable to respond' and risk factors that have been marked as 0/100 in terms of importance. All of these are indicated by a ‘0’. To support our interpretation of the results, please select 'Yes' to confirm that you understand that if you mark a risk factor as zero on importance, it will be interpreted as 'Not important' unless you have checked 'Unable to respond'."
However, when I download the data I see that 'Not Applicable/Unable to Respond' is treated as a blank cell, as are any sliders which have not been moved from the default of 0. I need to be able to distinguish between people saying 0 importance vs those who said 'Unable to Respond'. Is there a way to download the 'Unable to Respond' results so I can tell these apart (NB: I have renamed to this but it would be called 'Not Applicable' in Qualtrics).
thanks