Playlist order

I have a number of playlists for which I need to reset the tags. I'm able to do everything but one: I can't figure out how to get access to the sequential order of a file in the original playlist. The ordering is done manually and is not related to any of the available fields (filename, track, genre, etc). If I go into Customize Columns and try to define the column based on available other fields or functions, there doesn't seem to be anything like that "current sequential sequence number: that I can latch onto and put in the field.
Ultimately I would like to export the results, but in the order of the original playlist with the order number attached as a new field. Is this sort of thing possible? Thanks in advance fo your attention to this. If the answer is already somewhere in the help or the FAQ I apologize, I just haven't found it.

According to this German thread from 2004 /t/1013/1
you can simply d&d the playlist into MP3tag which keeps the order of the playlist.

If you now want to number the files, use an action of the type
Format value for (the user-defined) field %my_counter%
Format string: %_counter%

Thank you very much for the quick reply. Once I figured out how to do what you said (I'm new at this) it worked like a charm!

Further to this, again I am very new to this but quite excited about the power of this program, but I need some basic help. In the specific problem I had the solution involved a specific entity %_counter%. This is not a column (it's not listed in the "Tagged Field Mappings" in the help) but an "information field" whose value is the count of all selected files up to and including the current one, so that it takes on the values 1,2,3,... for each successive file as you move down the list of selected files.

So, my question is, is there a list of the information fields together with their meanings? I imagine it's somewhere in help but I can't find it.

%_counter% is mentioned in the converter-section.

Thank you! Perfect!