Click on the selection button […] at the top right to open a standard Windows file-open dialog. Navigate to the location of your spreadsheet file, select it and click 'OK'. If the spreadsheet is successfully imported, the grid will be populated with its values and the row set as the 'Starting units row' on the 'Set Defaults' page will be selected (denoted by a small triangle in the far left box in the row).
If you are importing a CSV format file, make sure you have selected that file type and entered the necessary information into the field format textboxes.
If you intent to use the "Copy All" feature you must make sure that the records in your file match the regional center's invoice exactly before importing the file.