Using a separate table to split records to fields in Power Query

Hello there!

I have multiple big, big text files containing ten-thousands of records, and more than hundred fields per records where the fields are not separated by anything and are varying length. (I mean varying from one field to the next. They are consistent from one record to another. Otherwise I wouldn't even bother.) Like so:

13051980011120...
11091991101021...
...

And I also have a nice table that contains the name of each field and how long each field is which I can easily expand to contain what position each fields starts at as well. Like so:

DeptId, 4
DoB, 8
TitleId, 2
...

Is there a way to use this table to tell Power Query to split up my long records accordingly? Neither Split Columns nor Text.Range is much fun if you have to manually repeat it more than hundred times.

I know I could technically put the table in the first row of a spreadsheet, transposed, and I could paste the big records in the first column and use Mid() to split it up, then import that into Power Query but this is a lot of formulas and also I was hoping to bypass copying/pasting by creating a query from folder.

Thanks a bunch in advance, even if it's a fool's errand.