I've worked on this problem in the past for modernization and migration away from legacy languages to modern ones. You need to write a parser for the source lan

I've worked on this problem in the past for modernization and migration away from legacy languages to modern ones. You need to write a parser for the source language, but that is a one-time upfront cost. The parser should populate an intermediate language agnostic model and then you can write as many generators as you require to translate that agnostic model into your target language of choice. We had one-click solutions for COBOL to C, Java to C#, VB to Angular, etc. Once you have the parsers and generators the work for each project after that is minimal.