Add SQL Count Column To Existing Table

I have a table for blog comments I want to add a column that counts the number of comments for each article.

existing table looks like this:

CommentID

ArticleID (FK)

commentAuthor

authorEmail

comment

commentDate (getDate())


I would like to add a column that counts the number of total comments for each article.This will give me what I want using the VS query tool:

"SELECT COUNT(comment) AS Expr1 FROM UserComments WHERE (articleid = @articleid)"

But can I add that to the table somehow so it does it automagically???