Short answer:
No. There's no mechanism in CHDK to start a script from another script as if it were selected in the script menu and the shutter button pressed.
Longer answer:
In Lua, you can run Lua code that resides in another file in various ways. Generally, to run another standalone script, you'd want to use the same pattern as running a camera side script from PTP, as described on
https://chdk.fandom.com/wiki/Lua/PTP_ScriptingYou'd need to provide "glue" to set any menu parameters, or code the second script to get settings in some other way.
You should be able to set the selected script with set_config_value, but you'd have to press shutter again to run the next script. You can also assign scripts in the user menu, but this again just selects the script and opens the script options.
