Changing a variable based on output

Good Afternoon, Just want to start by saying I am totally new with PS, and am really sorry if my approach to this is long winded or inaccurate.

I have a list of computernames that declared as individual Variables that my colleagues have provided me :

$Jon = "Abc1234"
$Mike = "Abc6789"

• another 10 hostnames

I then ask the user if they want to send the files to another PC :

$Targetuser = Read-Host 'Who would you like to send it to?'

What I would like is the output from the above to change to the hostname, but I am unsure of how to do this. Essentially, if the output was Mike, to change the $targetuser variable to $Abc6789

Thanks in advance