Relink batch to files with same name but different extension

I'm just new to Premiere Pro CC and noticing that working with .mts files is a lot slower than ProRes 422 Quicktime files. Now I'm trying to relink all that .mts footage to files of the same name converted to ProRes which works fine if I do it one by one. Unfortunately I have over 500 clips I need to relink and hope there is an easier way of doing this. It seems I need to relink to a filename instead of just selecting a folder where that file can be found. Is there a proper workflow for this I’m missing?

Thank you,

Rogier

using: OS X 10.9.3, Premiere Pro CC 7.2.2