Just like the title suggests copyToClipboard does NOT work on CLIENTS in MP environment.
Tested it several times and came to conclusion that its BROKEN or was DISABLED by BI Dev Team.
Please FIX or bring back this useful Command back to Clients in MP!
BTW - There's no explanation about the Command being REMOVED or DISABLED for Clients in MP on http://community.bistudio.com/wiki/copyToClipboard