insert call nstruction

Dear all
How can I insert a call instruction in my code from within the interpreter?
What I want to do is to stop interpreter at arbitrary instruction and change IR code by adding a call instruction for example in the comping code.
Could you please explain how I do this?

Regards,
Marwa Yusuf
Teaching Assistant - Computer Engineering Department
Faculty of Engineering - Benha University
E-JUST MSc Student
Computer Science & Engineering Dept.