Inserting numbers from a list in a repeating sentence

I have a list of all 5 digit combinations possible and I also have a sentence in which I would like to add each number. Here's an example:

• List items:

11111, 22222, 33333.. etc

• Sentence:

Hello userXXXXX, how are you?

• Desired result:

  1. Hello user11111, how are you?
  2. Hello user22222, how are you?
  3. Hello user33333, how are you?

The list of numbers is huge and the sentence keeps changing. I need a way to do this automatically.

Is such a thing possible?