Excel 2003-How do I conditionally reference cells from one worksheet to another?

I need to conditionally reference rows of cells from one worksheet to another. Specificially, I want to copy certain rows from one worksheet to another ONLY IF there is a "Y" or a "?" in a certain column. I want to leave any rows that have an "N" in the column, so in all, I have three variables: "Y & ?" should trigger the reference copy and "N" should leave the data on the main worksheet.
I am able to copy cells presently from one worksheet to another using the simple "=" function. I just would really like to do this conditionally so I get only the rows that I need.
Any help would be tremendously appreciated! Thanks!