Hey JM,
You’ve found a solution, but let me answer your original question.
To simulate opening files by dragging and dropping to an app-icon in the Finder:
tell application "Finder"
set finderSelectionList to selection as alias list
if length of finderSelectionList = 0 then error "No files were selected in the Finder!"
open finderSelectionList using application file id "com.apple.TextEdit"
end tell
And for that matter the open verb is universal in AppleScript, so something like this should generally work even if an app is NOT scriptable:
tell application "Finder"
set finderSelectionList to selection as alias list
if length of finderSelectionList = 0 then error "No files were selected in the Finder!"
end tell
tell application "Editra"
if not running then
launch
delay 0.5
end if
activate
open finderSelectionList
end tell
-Chris