There are a few different ways to automatically load add-ins in Excel. One way is to use the LOAD command. This command will load an add-in every time Excel starts. Another way is to use the auto_open macro. This macro will automatically open an add-in when Excel starts. Finally, you can use the registration method to register an add-in so that it loads every time Excel starts.

To use the LOAD command, open the Excel Options dialog box and select the AddIns tab. In the Manage dropdown, select Excel AddIns and click Go. In the AddIns dialog box, check the box next to the addIn that you want to load and click OK.

To use the auto_open macro, open the Visual Basic Editor and insert the following code:

Sub auto_open()

   'Add your code here
   
End Sub

Replace 'Add your code here' with the name of your addIn (without the .xlam extension). Save your workbook as an .xlsm file and close the Visual Basic Editor.

To register an addIn so that it loads automatically when Excel starts, open the Registry Editor and go to HKEY_CURRENT_USER\Software\Microsoft\Office\Excel\Addins\. Create a new key under Addins for your addIn (without the .xlam extension). Set the Default value for this key to 1.