Add sequential numbers to exported names?

I have 300 clips exported from premiere pro, they are all in order on my time line. I place them in a bing and then send to media incoder. They are all in perfect order, but when I export them, they are all over the place. No matter how I sort them, by date created, name, etc. they are all out of order.

I looked up adding sequential numbers automatically to the exported files and two options are "add a # sign to the file name and they will be automatically numbered" but to do that I would have to manually go through 300 clips and add the # sign to each one. 

The other option was to "create an ingest preset" but the feature to modify exported file names seems to be gone from there.

Is there any possible way to add sequential numbers to my file names or just keep the files in order when I export them? It's a music playlist and they must be in order.