All the answers are already there, you just have to
deploy them in your example.
Use thread number like shown seems best sollution.
Nevertheless there is one more choice you have and
it is using resources.
You can create a new resource and use default settings - lines from file, so bas will use this resource only once per line accross multiple threads - whatever number you set, in
your current case 3 threads.
You would use resource lines from file only as pointer for
your actions just like with THREAD_INDEX. And you also need
simple if checking to determine what current thread should do.
So you can create text file with number of actions you have and
single letters wont be enough for 100+ actions, use numbers instead and put one number in each line from
1 - 100 for example. When start bot with 3 threads it will
use first 3 numbers from list and continue as you described as desired
until it reach end of resource list which will cause bot to stop
under default settings.