That is an entirely manual process and requires someone to actually translate the code between the two languages. Much like an interpreter translates spoken language. In almost all cases, computer code is specific to a given platform and does not work on any other platform. Which is why you cannot simply copy the code from one platform and pasted it on to another.
Is it possible for someone to translate a chart strategy from Thinkorswim to TradeStation? Yes, I have completed many custom projects for clients and I can translate code between these two platforms in both directions.
If your Thinkorswim chart strategy breaks any of the rules for back-testing it will need to be corrected before it can be translated to TradeStation. What does that mean? I means that Thinkorswim lacks the safeguards included with TradeStation and its very possible to create a chart strategy on Thinkorswim that produces results impossible to replicate on in real life. TradeStation strictly enforces numerous safeguards, which ensures that any chart strategy written for TradeStation will work in real life.