After searching to no avail I don't think this is impossible just even if similar there is really no reason to actually make an automated script to convert.
The time it would take to automate it would be around the same as rebuilding when you already have the as3 code as an example. A plain conversion would lead to many more issues then it would solve. But when rebuilding it would be built to compensate for those issues.
So my recommendation for anyone attempting this is to just rebuild it, flash and javascript run in 2 different environments so its a lot less pain in the long run to just do a rebuild.