Automator creation of file names in 3rd party exports

Firstly, I'm a novice in automator & applescript. I have however managed to create an automator workflow that falls over at the second iteration. What I am trying to do is the following: working in Sierra I have an old app (Discus) that has an export capability for graphics that reside in the app. It appears that Discus does not have either AppleScript or Automator built in.

The workflow has the following steps: move cursor direction right one keystroke (working) / select export from the menu (working) / keystroke a unique file name for the export file (not working) / save to folder (working) / Loop x1000 (working).

At the moment the workflow falls over the second time it attempts to name the export file. I cannot find a way to auto create a new name for each iteration. Consequently Discus hangs waiting for a decision on whether to overwrite the initial exported file or to create a new filename.

It would be beneficial to create a new file names using sequential numbering. There is an action for doing this in the finder, however this does not work in the workflow as I presume the file saving action is taking place in Discus, not in the finder.

Any ideas on how to overcome this, or evenif it's possible. It may be that Automator in Sierra is more limited in capability than in current Mac OS? Thanks