The only good news I have for you is that you can stop spending any more time trying to get this to work on Thinkorswim. Along with that you no longer need to spend any more time trying to find someone who has figured this out for Thinkorswim.
Why? Because it is totally impossible to do this on Thinkorswim given it's current suite of programming tools. We cannot even get close. There are no custom arrays in Thinkorswim and there is no way to write code for Thinkorswim that is able to loop through a set of strike prices, check which ones exist and assemble a list of available strike prices.
I could go on to describe the many other limitations that make this completely impossible for Thinkorswim, but until we can accomplish those two simple things none of the other hurdles are worth discussing.
Looking for trading platforms that just might be able to pull this off?
- Sierra Chart
I know some folks will be tempted to ask for a solution built for one of those platforms so I will provide that answer now. An indicator of this type is extremely expensive to build. If you find one that is already built and available for another platform you should expect to pay several hundred dollars for this. If you wanted to hire someone to build this from scratch it would cost several thousand dollars.
Solutions of this type are light-years beyond the scope of solutions we can provide free of charge in this forum.