The closest to this is to use BigQuery over HTTPArchive, it's not the Google index but a pretty solid base though and requires no setup at all.

https://github.com/HTTPArchive/legacy.httparchive.org/blob/m...

You can search for anything in the source-code of pages, using any regex or grep you can imagine.

Get a job at Google and then you can directly query the underlying data with as complex a query as you like (and don't have to use indexes etc).

Obviously running your custom filter logic across every byte of data that has ever existed on the internet is compute heavy... But Google has lots of that!