const regex = /\h*(\d*)t(\d*)o\+?p\+?:\h*/g;
// Alternative syntax using RegExp constructor
// const regex = new RegExp('\\h*(\\d*)t(\\d*)o\\+?p\\+?:\\h*', 'g')
const str = `F 1t2op+:vAWGPHGM
F t12o+p: vAWGPHGM
F1t2op+:vAWGPHGM
F 12top+: vAWGPHGM`;
const subst = `$1$2+ `;
// 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