dbo.Split is not a built in function. They're referencing building a function to do that, such as the following:
http://www.sqlservercentral.com/articles/Tally+Table/72993/
What you basically do is turn the comma delimited string into a temp table, and join against it as your IN clause. I typically write these as:
SELECT
fieldlist
FROM
table
JOIN
splitter(@parameter) AS s
ON table.field = s.field
Never stop learning, even if it hurts. Ego bruises are practically mandatory as you learn unless you've never risked enough to make a mistake.
For better assistance in answering your questions[/url] | Forum Netiquette
For index/tuning help, follow these directions.[/url] |Tally Tables[/url]
Twitter: @AnyWayDBA