If you are planning to work with a lot of copying and pasting between different CadTools input grids it’s a god idea to turn off the setting for using Excel. This will prevent Excel from starting and instead send all results to CadTools simple spreadsheet. This is much faster than sending data to Excel and you don’t need to close the spreadsheet window between commands, it updates simultaneously
I you want to do some calculations you can always copy and paste between the spreadsheet and Excel. You’ll find a checkbox in the settings dialog “Excel isn’t installed on the computer”