Powershell regex for replacing text between two strings

Question

I am trying to use a powershell script to change the password between two strings, I am running into two issues.

1. A complex password seems to break my regex, If

Answer 1

This person had a similar issue that I was able to use the regex in my code:

Hide passwords in string

I ended up with the following:

#Set new password in server.xml
$pass='6QAfD5PmMhWzUxTq1FO1bGJQQXRXu6tizN29h6MRUSI='
$server_xml=".\server.xml"
(Get-Content $server_xml) -replace '(?:(?<=keystorePass=")\S+(?="))',("$pass") | Set-Content $server_xml