Collection based on PC name using Regex/pattern matching?

Try this:

^([A-Za-z]\w+)(\d+|-[Nn][Ee][Ww]|-[Oo][Ll][Dd])
[A-Za-z] matches any letter
\w matches any alphanumeric character
\d matches any number
+ is a quantifier saying match 1 or more of the preceding token
| means OR
The parentheses are just here to encapsulate a token so the OR logic is more obvious

- literally matches a hyphen
[Nn][Ee][Ww] matches any capitalization of "new"
[Oo][Ll][Dd] matches any capitalization of "old"

This won't match ##demo# since it won't match anything that begins with a number.

Regular expressions are case insensitive in Inventory. Here's my submission:

^[a-z]\w+(\d+|-(new|old))

I tested my pattern in PowerShell because Inventory and PowerShell both use .NET regex.

$TestStrings = @(
    'TEDPC'
    'tedpc-NEW'
    'ZENITH-LT'
    'Accounting3'
    'ceo-old'
    'C3PO'
    '10demo1'
)
$Pattern = '^[a-z]\w+(\d+|-(new|old))'

foreach ( $TestString in $TestStrings ) {

    [PSCustomObject]@{
        'Test String'     = $TestString
        'Matches Pattern' = $TestString -match $Pattern
    }

}

Awesome thanks guys. I used Colby's because it's a bit easier to read. Works great. Luke's works as well if you add ^ to the beginning otherwise it picks up those demo names. Thanks both of you for the assist!

Thanks Colby, I didn't realize that regex was case-insensitive in Inventory.

Glad it worked out for you, Craig.