Is there a url where I can test the search functionality? What version of DataAssist are you using?
Case sensitivity is controlled by the data type of the columns you are searching. You can update your collation settings for the column to use either a case sensitive or case insensitive collation. For instance "latin1_general_ci" or "latin1_general_cs".... the cs or ci at the end stand for case sensitive or case insensitive.