Batch Convert PowerPoint to Movies file name issue

Question

I need to batch convert powerpoint presentations to movie. But the save option forces me to use the same name on every movie. I want it to just save the presentation with the same file name. So if the powerpoint is:
MyPresentation.ppt
then the movie should be
MyPresentation.mov
How can I do this?
Here is a screenshot of the workflow.

Answer 1

Okay, so I tried ditching automator and doing the convert movie parts via applescript. This is what I tried but it gives me an automator error -212 (apparently on the first "perform action") saying "expected end of line, found property":
Any ideas on how to get the script to work with autmator (I tested a modified version of this script outside autmator and it does work for a single file).
on run {input, parameters}
  -- Use the "Make Movie..." command in PowerPoint to make a QuickTime movie
          tell application "System Events"
                    tell application "Microsoft PowerPoint"
  launch
  open input
                              set frontmost to true
                              set theNameOfPresentation to title of last window
  -- Click on the Save as Movie... command in the File menu
                              perform action "AXPress" of menu item "Save as Movie..." of menu 1 of menu bar item "File" of menu bar 1
                              repeat until ((exists of sheet 1 of window theNameOfPresentation) is true)
                              end repeat
  -- Enter the name of the Presentation
                              set value of text field 1 of sheet 1 of window theNameOfPresentation to theNameOfPresentation & ".mov"
                              delay 2
  -- Click on the Save button
                              perform action "AXPress" of button "Save" of sheet 1 of window theNameOfPresentation
                              delay 2
  close input
                    end tell
          end tell
          return input
end run