Pele,

           If you happen to know Linux/Unix, the awk command will be very easy to use to do the conversion.

A JAWS dictionary line has the fields, in order:  Actual word|Replacement Word|Language (0x09-English)|Synthesizer|Voice|Language (0 is default)|Case sensitive (0 - No, 1 -Yes)
For the JAWS dictionary, the fields themselves are DOT enclosed/separated, UNLESS, the actual word starts with a dot, in which case it's a comma used for the separator.

The NVDA dictionary file layout is simpler, and the fields are tab separated.  The first field does not have a separator before it.  They are arranged as:
Matching word or regular expression|Replacement|Case Sensitivity (0 - no, 1 - yes)|Type (2 - Whole Word, 1 - Regular Expression, 0 - Anywhere)|Comment (All comments are pre-pended with a #

For both dictionaries, there is a single entry per line of the file.

Have fun with it.  It doesn't appear to be particularly complicated.
--

Brian - Windows 10 Pro, 64-Bit, Version 1909, Build 18363  

Science has become just another voice in the room; it has lost its platform.  Now, you simply declare your own truth.

      ~ Dr. Paul A. Offit, in New York Times article, How Anti-Vaccine Sentiment Took Hold in the United States, September 23, 2019