And, for the record, “the key piece of magic” is the /g, and possibly also the /c, modifiers, which are described under, of all places, “Regexp Quote-Like Operators” in perldoc perlop.   (As referred-to in the main regexp topic, perldoc perlre.)

These two modifiers allow you to search repeatedly within a single string, in a while-loop as shown, using groups (in parentheses) to extract each part that has been matched.   As shown in examples given earlier, this lets you “roll-up” such a string, viewing it exactly as the CNC designers intended:   as a list of one-or-more variable/value pairs having no set delimiters between them.   (Delimiters being unnecessary because alpha characters are distinct from digits and decimal points.)