How can I implement symbolic execution
for particular language
without using model checking
and Finite State Machine (FSM)
You need:
This is rather a lot of machinery, and it is hard to find it all in one place. It is harder to build it all just for one tool, which is part of the reason you don't find many tools like this.
Our DMS Software Reengineering Toolkit has all the requisites. You may find an example of a symbolic language implemented with DMS interesting.