What you could try, is to pass a variable value in the URL and then trigger an action based on the variable change.
In the URL you can add the variable as int he example below;
There is no built-in action that allows an Excel export, so the best option could be a ServerSideExportEx macro. The macro is defined in the QlikView macro editor, press Ctrl+M when you are in the QlikView desktop client. This macro will however store the export on file on the server side, which I guess is a feasible solution if you execute the export from a PowerShell script.
You can find the ServerSideExportEx definition in the API guide;