GIMP :: Create Series Of PNG Files From Existing Image

I'm using the script export-selection.scm to create a series of PNG files from an existing image. It works fine but I find the fact that it saves the file to a name that it constructs (based on the .xcf file loaded, and whether it is saving a one layer or visible layers, etc) really slows me down, as I have to bounce between gimp and explorer to rename each output file after every save.

I looked at the source to see if I could tweak it so that the filename it created was unique, but I must have missed a crucial episode somewhere, because I couldn't get past first base.

Here's the candidate line from the script:

(outputName (string-append imageNameNoExt "-sel"))

..so you get a filename of MyGimpImageName-sel.png. What I want to do is create filenames called MyGimpImageName-sel-001.png, MyGimpImageName-sel-002.png etc.

An alternative would be to add an edit box to the dialog to allow you to specify the filename.

On a related subject, is it possible to set up a key binding to execute a script? If this could be done, I could roll a version of the script that skipped the dialog altogether and just used the last settings. In combination with the unique filename mod, this would speed up the job considerably.