source: https://discussions.apple.com/thread/1485146
To run another script file:
run script "HD:path:to:file.scpt"
You can use POSIX file to coerce a Unix path into a Mac path/alias — see the next section.
source: http://www.satimage.fr/software/en/smile/external_codes/file_paths.html
Where POSIX uses the slash / as the separator for directories, AppleScript uses the colon :.
You can use colon : in a POSIX file name, and you can use slash / in an AppleScript file name: they translate one into the other.
To translate a UNIX path (file or directory, valid or not) into an AppleScript file reference, use POSIX file. POSIX file returns a file reference, that your script can use directly to create or use the file.
set p to "/usr/local/bin/" set a to POSIX file p *-- file "Macintosh HD:usr:local:bin:"*
To translate an AppleScript path (file or directory, valid or not) into a POSIX path use POSIX path of.
set a to "Macintosh HD:usr:local:bin:" set p to POSIX path of a *-- "/usr/local/bin/"*
POSIX path also understands AppleScript's file references.
set a to alias "Macintosh HD:usr:local:bin:" set p to POSIX path of a *-- "/usr/local/bin/"* set a to file "Macintosh HD:usr:local:bin:" set p to POSIX path of a *-- "/usr/local/bin/"*