tell application "Finder"
activate
open folder "path:to:folder"
select item "filename" of window 1
end tell
osascript -e 'tell application "Finder"
activate
open folder "path:to:folder"
select item "filename" of window 1
end tell'
tell application "Finder"
activate
open folder POSIX file "/path/to/folder"
select item "filename" of window 1
end tell