Hi, alas it is not possible – if you can open the schedule, you see everything in it. What I would do instead is export the data that you want the customer to to see into excel, and then rebuild a new schedule from the excel file and send that to the customer. It sounds complex, but is very easy as Project allows you to create a map, which matches the fields from Project to/from Excel.
I’ve done this in various instances, almost always to remove costs, and it is a 5 minute job only. The first place to start is Save Asv and choose the Excel format. Please post again if you are having issues.