[QSF] how to use variables + how to include another script?

Hi All,

1) How can I use the local/environment variables inside of the QSF file?

Howsome the regular TCL variable assignment does not work for me:

%> set a "AAA";

2) How to use the source_tcl_script_file in the following command? How should it work?

%> set_global_assignment -name source_tcl_script_file "<path>/vars.tcl"

3) inside of the QSF I've put the following line:

source <path>/<filename.tcl>

The <path> is an absolute path to the file and the file is physically exists in its location, but Quartus Prime issues an error message that it cannot find the file.... Why? How to fix?

Thank you!