SQL Expressions

I guess I really have 2 questions.

I am moving an application from Sybase over to SQL Server. I have created all of my tables. I have also created Scalar-value functions to return a total of a column from a child table based on a value from a master table. The reason I have done this I have multiple child tables that I want to return total on and I would have ahd to create subreports to retreive these totals.

My question first is "How do you call an SQL Expression and could some on show me the code"?

Second question is if I wrote a command to retrieve this scalar-value how would I pass the parameters?

Finally, I guess there were three questions <g>, Should I just go ahead and write the View over in SQL Server and use that for my report?