Regular expression example (Capturing groups) for https://powershell.org/forums/topic/regex-replace/

powershell-forum-regex-replace-reply-02.ps1

$text = 'info@example.com'

# Example 1: Unnamed capturing group
if ($text -match '@(.+)$') {
    # Output the complete match
    $Matches[0] # @example.com

    # Output only the value of the capturing group
    $Matches[1] # example.com
}

# Example 2: Named capturing group
if ($text -match '@(?<DomainName>.+)$') {
    # Output only the value of the capturing group
    $Matches.DomainName # example.com
}

# Example 3:
#     Replace domain name and use a back reference to access 
#     the value of the capturing group with the mailbox/user name
$text -replace '^(.+)@.+$', '$1@test.com' # Outputs: info@test.com