Script help

1 ) Can someone show me how to call an erxternal task in a text script file

then wait till i restart it to complete the rest of the script file

or from a button on a GUI

2 ) Where can i find a list of script names for the variables that we see
on Blender’s menu

Like color - What are the variables in a script file would allow me to change the color of a selected object from GUI in a Text script file.

Tanks & Salutations