const regex = /.+(?=(?:AN|N)-\d+)|(?<=(?:AN|N)-\d+)\s.+/g;
// Alternative syntax using RegExp constructor
// const regex = new RegExp('.+(?=(?:AN|N)-\\d+)|(?<=(?:AN|N)-\\d+)\\s.+', 'g')
const str = `2 BILLING ID AN-19 RPS Ex : “00411850177 “
3 FILLER AN-11 RPS EX: “ “
4 FILLER AN-15 RPS EX: “ “
5 FILLER AN-30 RPS EX: “ “
6 FILLER AN-2 RPS EX: “ “
7 FILLER AN-1 RPS EX: “ “
8 BILLER CODE AN-4 RPS Ex : “1310” 1302 means PDAM Mitracom
9 FILLER AN-11 RPS EX: “ “
10 ADMIN FEE N-12 LPZ Ex : “000000075000”
11 FILLER AN-11 RPS EX: “ “
12 FILLER AN-12 RPS EX: “ “ `;
const subst = ``;
// The substituted value will be contained in the result variable
const result = str.replace(regex, subst);
console.log('Substitution result: ', result);
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for JavaScript, please visit: https://developer.mozilla.org/en/docs/Web/JavaScript/Guide/Regular_Expressions