Action droplet that saves in same folder with suffix?

I'm trying to record a set of actions that includes a save command that saves the file in the same folder (regardless of where the file is) with a suffix. The process for each filename would be:

1. Drag filename.png onto a droplet

2. Do stuff

3. Save file.png as filename_new.png in the same directory as the original

I haven't figured out if it's possible to do this without scripting (haven't learnt this part yet). With actions I either overwrite the existing file with the changes or set the output location to save to a specific folder. Is it possible to ignore the location and save in the same directory but with a change to the filename instead of overwriting the existing file? It would be useful if I were to distribute the droplet without worrying if that directory exists or not.

Any help is much appreciated.