Use the built-in Python AST parsing module. Invoke Python from Common Lisp (SBCL) using C API bindings.
From https://www.linuxjournal.com/article/8497
Docs are here: https://docs.python.org/3/library/ast.html
Run python-config for compile/link flags if needed.
Py_Initialize();
PyRun_SimpleString(code);
Py_Finalize();
Implement in Python the translation to Common Lisp, have the Lisp system eval the result of the Python translation code.
SBCL Foreign Function Interface: http://www.sbcl.org/manual/index.html#Foreign-Function-Interface
Just treat Python functions as normal variables and always use #'apply or #'funcall to invoke them in the generated Lisp code.