Swift Localization: String String interpolation - swift

Question

I am trying to add multilanguage support to my app. I am doing this by replacing all my User visible Strings with localized strings. For strings like "Cancel", this is easy. But I have just as many strings that are interpolated with information. And the hard part is that each language would build the sentence differently.
For example: How would I localize the following String:
"Please enter the 4-digit Code sent to you at (user.PhoneNumber)"
In German, I want the string to look like this:
"Bitte gebe den 4-Ziffer Code ein, den wir dir an (user.PhoneNumber) gesendet haben"
Or in French:
"Entrez le code à 4 chiffres qui vous a été envoyé à (user.PhoneNumber)"
I am trying to find a way to use some kind of variable inside of my localization file like this (I know that this does not work):
Inside my ViewController:
title.text = "Please enter the 4-digit Code sent to you at %phoneNumber%".localized
Inside my Localizable.string
"Please enter the 4-digit Code sent to you at %phoneNumber%" = "Bitte gebe den 4-Ziffer Code ein, den wir dir an %phoneNumber% gesendet haben"
What's the best practice to do this? This must be some common issue people are having. Languages are so different!

Answer 1

my localized file example:
"email_error_message" = "a link is sent to %# please verify"
Actual code implementation:
let email = smth#email.com
let message = NSLocalizedString("email_error_message", comment: "error, wrong email")
let str = String.localizedStringWithFormat(message, email) //we want to replace %# with email.
Print(str)
** Please note the replaced string/char, in the above case (email) won't be localized.