Multi Artist/Remixer formatting

I've recently moved the Artist field of my music collection over to a new method of formatting:

Artist1&Artist2\\Remixer1&Remixer2

So for example if Artist 1 released a solo track the field would say:
Artist 1

However if Artist 1 Decided to collaborate with Artist 2, it would say:
Artist 1&Artist 2

Then if Remixer 1 remixed that track, it would say:
Artist 1&Artist 2\\Remixer 1

And if Remixer 1 collaborated on the remix with Remixer 2, it would say:
Artist 1&Artist 2\\Remixer 1&Remixer 2

Now, if Artist 1 had a guest singer (a "feat."), it would say:
Artist 1&Artist 2:Singer 1\\Remixer 1&Remixer 2

My question is how can I make an action that can read this and format the file name as such:

Artist 1 & Artist 2 (feat. Singer 1) - %title% (Remixer 1 & Remixer 2 Remix)

Just for this case ...

Action "Format value" Field ......: _FILENAME Formatstring: $validate($replace($meta(ARTIST,0)')','&',' & ',':',' (feat. ')' - '%TITLE%' ('$replace($meta(ARTIST,1),'&',' & ')' Remix)','_') From: 'Artist 1&Artist 2:Singer 1\\\\Remixer 1&Remixer 2' To : 'Artist 1 & Artist 2 (feat. Singer 1) - Some Title (Remixer 1 & Remixer 2 Remix)'

DD.20150905.1822.CEST