it is not easy to understand your request but I tried some basics with 'eval', which herein is one of my extension functions:
~~~
sandbox>sqlite3.exe
SQLite version 3.36.0 2021-06-18 18:36:39
Enter ".help" for usage hints.
Connected to a transient in-memory database.
Use ".open FILENAME" to reopen on a persistent database.
sqlite> select typeof(X'010203');
blob
sqlite> select eval('select 3.1415');
Error: no such function: eval
sqlite> .load sqlite3.dll
sqlite> select eval('select 3.1415');
3.1415
sqlite> select eval('select '||X'010203');
unrecognized token: ""
sqlite> select eval('select typeof('||X'010203'||')');
unrecognized token: ""
sqlite> select eval('select typeof("'||X'010203'||'")');
text
sqlite>
~~~