Use this field to type in your own customized filter using regular expression syntax. For example, the filter /^a.*\.cel/i reads all .cel or .CEL files that begin with the letter a , regardless of case. If you specify this parameter, it overrides any specification in the File Filter Expression parameter.Refer to the SAS Online Documentation for the PRXPARSE function for additional details.
Type the expression into the Custom File Filter Expression text field.