You can implement exSelQueryExportFileExtension. There, based on the parameters, the plug-in can specify the file extension. You could add a parameter, perhaps a radio button, for the user to choose file extension. Or you may wish to automatically set the file extension based on a combination of parameters.
I know that, but still want to change extension by just changing the output name Just don't want to use dropdown box/radio buttons to choose the file type. But thanks for clarifying anw.