You need timecode and reel name. Take a look at VideoToolShed's QTChange. It will allow you to create separate QTreference (Testclip) files with TC, and that will make this process a lot easier.

Thanks, SMPse, I'll have a look.

In the meantime, do you know if there is any way to re-link a clip (in this case with an AX reel name) with a different source file in LW? In some other NLEs there is an option to "replace file"/"change source file."

Just to contradict one of your assumptions. In production when it come organisation of material there is nothing special about a cassette of tape that differs from a current camera card. Neither of them has an intrinsic reel number - the user should assign a reel number to both and often, over the course of a production, both might be recycled as completely different reel numbers

A project based unique reel number and time code properly used - that is definitely not duplicated on any one reel and, in the case of re-digitizing from tape, in ascending order and preferably not passing through midnight are at the heart of conforming to EDL protocols. File names are not important to an EDL.

Sure, if you can organise your unique HDD locations into reel numbers and add that information to your premier edit as well as your original material before importing the EDL then LW will find the correct material to fill your edit.

Thank you for your answer, RWAV. Believe me, I'm not intentionally trying to be difficult or obtuse, I'm just trying to solve my problem at hand.

I understand that most EDLs use reel and timecode, and if I'm using one of the current batch of DSLRs that doesn't affix reel and timecode, then I'm out of luck and can't use those EDL formats (or I have to use a product like FCP's Log and Transfer or QTChange to affix reel names and fudge timecode). I'm happy to accept that.

The initial question was whether there was a way to modify the EDL through Perl using the video file path so that it would be readable by Lightworks. So perhaps I would be better off just sticking to that question: can Lightworks import a CSV or cut list with some version of: file name, time in, time out?

For anyone who might have been following this thread, here was my workaround. It's pretty ugly, but it did what I needed it to do:

1) import all of my media files into a bin (using the option "Create Link" to save time) so that LW creates a cookie for each file.
2) export a database of that bin with "Save to text file." The database is a CSV file that, among other things, contains the LW cookie and the original file name.
3) using Perl, replace instances of the file name in the Vegas EDL with the corresponding LW cookie. Convert times to hh:mm:ss:ff because the Vegas EDL gives time in milliseconds. Export a CMX3600 formatted EDL.

So in the end, an entry like this:
1; 0; 0.000000; 14436.000000; 1.000000; FALSE; FALSE; 0; TRUE; FALSE; AUDIO; "O:\myfilm\MVI_0802.MOV"; 0; 8522.676688; 14436.000000; 0.000000; 0.000000; 1.000000; 2; 0.000000; -2; 0.000000; 0; -1; 0; 0; 0.000000; FALSE;

was changed to this:
001 E00300AA AA/V C 00:00:08:08 00:00:22:22 00:00:00:00 00:00:14:14