IF statement based on topic's word count?

[mark7144]

Hello, I'd like to have an IF statement based on word count of a topic's page. So for example, if topic page (including replies) has less than 300 words, then insert meta tag robots=noindex. 

Although word count itself might not be directly related to Google Panda's "thin content" algorithm factor , this code would indirectly help as threads with only a few words are often of little value to the reader.

Pleased can someone help me with this?