list into string

ok, i got a problem and there are one of two ways to fix it, one is more logical so i'll ask it first. i want to transform a list into a string to use it in a macro. i know about https://discord.com/channels/935560260725379143/1283418798850052096/1283418798850052096. but his question wasnt really answered, strings are able to be used in macros, so if there is a way to transform it into that, that would be amazing. ill provide an example below.
turning the list ["1","2",3"] into "123" 
turning the list ["1 ","2 ",3 "] into "1 2 3" 
without the commas would be optimal, but isnt required
and yes i do need it to be the entire list, i cant just do list[0] as that is hard coded and my datapack isn't.