Convert formatted contents notes to unformated - example 2

Question:

I wonder whether anyone has found a way to convert formatted content notes to unformatted. 

An example is:

=505  00$tOn comparison /$rJonathan Z. Smith --$tPolis-religion and its alternatives in the Roman provinces /$rGreg Woolf --$tFrom republic to principate : priesthood, religion and ideology /$rRichard Gordon --$tFeature of Roman religion /$rArthur Darby Nock --$tLudi saeculares and the Carmen saeculare /$rDenis Feeney --$tCults, myths, and politics at the beginning of the empire /$rJohn Scheid, trans. Philip Purchase --$tTheological efforts of the Roman upper classes in the first century BC /$rArnaldo Momigliano --$tHierarchy and structure in Roman polytheism : Roman methods of conceiving action /$rJohn Scheid, trans. Philip Purchase --$tReligious toleration in republican Rome /$rJohn North --$tReligion for the empire /$rClifford Ando --$tLoca sancta /$rSabine MacCormack --$tComplex of times : no more sheep on Romulus' birthday /$rMary Beard --$tRoman state religion in the mirror of Augustan and Late Republican apologetics /$rCarl Koch, trans. Christpher Barnes --$tHistorical development of Roman religion : an overview /$rGeorg Wissowa, trans. Christopher Barnes.​

To turn to 

=505  00$a[Contents]

by removing all subfields ($t, $r, $getc.) and keeping (or turning the first subfield) into $a.

See also:

=505  00$g1.$tModern purebred breeding : a scientific or cultural method? --$g2.$tThe light horse --$g3.$tThe heavy horse --$g4.$tThe farmer's horse --$g5.$tFinding horses for the British army --$g6.$tAmerican horses and war : a national and international issue --$g7.$tCanada's equine war effort : a story of conflicting interests --$g8.$tUnderstanding heredity : the 1890 report of the British Royal Commission on horse breeding --$g9.$tProducing better horses in the United States : attempts to control fraudulent activity and market share --$g10.$tThe Canadian experience in horse regulation : continental and national concerns --$g11.$tAspects of a pervasive horse culture in society --$g12.$tConclusion.

Answer: The answer is solved by MarcEdit develop, Terry Reese

1) Edit Field Data 

Field: 505

Find: (\$[a-z])

Replace: [blank or space or whatever you are turning the data into]

Check use regular expressions

Then you have to do a second step because this removes all delimiters -- and you need to add one back after the indicators.  You can do that with a replace function:

Find: (=505.{4})([^$])(.*)

Replace: $1$$a$2$3

check use regular expressions.