Hi,
Assuming you are using OutSystems in the cloud, it will have no connectivity to your local hard drive.
I would advise to use a cloud storage like Amazon S3 buckets to store your Excel files, then you can use the Amazon S3 Connector OutSystems Forge component and process the data in your OutSystems application.
Instead of AWS S3 Buckets, you could also consider Microsoft OneDrive, Google Drive for those also connectors exists in www.outsystems.com/forge
Regards,
Daniel