Need help Creating Aliases, Switching Alias as primary Exchange Email powershell

Hello folks, I need a script to create mass aliases and then make it a primary email + some extra later in the post

We have big list of users we now have to create aliases of the same for each user

example: get alias as and then this is set as his primary email address others are aliases

now once this is done we will have some users among all of these who will need an email change so this means that some users will get a 2nd alias and then this will be made as primary, yes to make it simpler we are trying to do it in 2 steps :) so some people will have 2 aliases on the some domain

example: get alias as

but we would now change his name from to

Please let me know if you would need more details on this, this is what we would need, there are more than a thousand users atm and doing it manually would be a pain :) Thanks