A Find/Replace "Step" for Custom Actions (with RegEx)

Feature Requests
31

I am trying to figure out how to use Find & Replace with RegEx to manipulate text. In this case, want to set a variable using RegEx and then replace text with the variable.

Text:

Mr. John Smith

Mr. XX goes to town.

Script

// define regex to use...
const findRegex = /([M][r-s]\.\s)(\w*\s)(\w*)/g;
// define replacement expression...
const FirstName = "$2";
const LastName = "$3";

//Find Text
const XX = "XX";
//

// do the replacement...
draft.content = draft.content.replace(XX, LastName);
draft.update();

Result:

Mr. John Smith

Mr. $3 goes to town.

What am I doing wrong?