Importing tags from one library to another

I have two libraries, one of MP3 files and one of flac. Each library has over 6000 songs but the flac library is a subset of the MP3. Everything is named the same between common files in both libraries. All the tags in the MP3 library are up to date. What I want to do is export the tags from the MP3 library, edit the export file to reflect the .flac file extension and the different file paths and then import the whole lot in the flac library updating-any matches. I have not found a way to do this so it "works". This issue appears to be the mismatch in number of files and the need to select files as part of the text file to tag import.

is there way to update a whole library from a file of tags so it updates whereit finds a match using %_Path% assuming for and skips what is missing?

Export format:
$filename(txt,utf-8)$loop(%_path%)%_path% / %artist% / %albumartist% / %album% / %title% / %track% / %discnumber% / %year% / %genre%
$loopend()

Export File:
M:\portable\Amorphis\Circle\01 - Shades of Gray.mp3 | Amorphis | Amorphis | Circle | Shades of Gray | 1/9 | 1/1 | 2013 | Progressive Metal

libraries:
M:\Lossless
M:\Portable

Thanks for any help.

I think you have to use %_filename% instead of %_path%
Also, the FILENAME should be included in the export data.
The example that you gave looks like a mock-up as the separating characters do not match.

Did you know that if you have the source files and the target files in the same order and selected matching numbers then you can transfer the tags with copy/paste from the source to the target. So the first target file gets the data from the first source file, the second from the second and so on.

See also here:

or here:

Thanks for the tips. I changed the delimiter in the export after I copied it. Everything's works if the files selected match the text file its when their aren't matches in the FLAC library when things break. I'll look at the copy and paste, that may be faster than trying to get this to work.

To import masses of data from a text file you have to use the function
Convert>Text file-Tag.
To get some alignment between data and files, you have add the filename, preferably %filename_ext% to each record, so append your report by this field.
After the export is generated, replace the source filename extension with the target filename extension, e.g. mp3 becomes flac.
Now try to import.