This plugin exports grades in xls file, adding two type of columns:
1. Group column, shows groups' name which students are enroled. In the "All participants" export (without selection of group), you'll see a row for each student-group couple, it means that for the same student could have as many rows as groups which he was affiliated.
2. Date columns, for each grade item, shows the last modification date for this item grade (Y.m.d format)
Copy the plugin directory "xlsgd" into moodle\grade\export\.
Check admin notifications to install.