well, excel files are recognized by the computer because the computer obviously has an excel program installed in it, and the application has a set icon for the files. if the computer doesn't have one, the excel file is supposed to look like one of those files you see with a weird icon.
for example, my program creates (saves) files under .jeb extension name. obviously, the computer won't be able to recognize it so it shows an the icon for unkown files. but if i have my icon specifically for my app's files, how can i put the code so that whenever a file under that extension is created, the icon that i used will be shown and not the weird looking icon?