Find 24 alphanumeric string

[derekjwu]

What would I type into the search bar to give me everything that is exactly 24 alphanumeric in length. For example, I have data that contains a randomly-generated 24 alphanum code I know that this code means "application" and NOT "Data" and I want to ONLY see application-related logs and time-report on them.

For instance, a code would look like this: 4j5233z72kch2axah32k3azp

[ziegfried]

sourcetype=mysourcetype | rex "(?:^|\W)(?<alnum_code>\w{24})(?:\W|$)" | table alnum_code

[satya2p]

Above code captures String as well, what if you want to capture only alphanumeric and not string.