ClipboardPaste "ask" vs "allow" (qrexec question)

[Dave C]

There's a comment in /etc/qubes-rpc/policy/qubes.ClipboardPaste:

## Clipboard paste (Ctrl-Shift-V) will treat "ask" as "allow" but only when
## called by this keyboard shortcut. "deny" always deny the operation

This begs the question: how can I paste into a VMs clipboard *not* via the keyboard shortcut?

Can qubes.ClipboardPaste be invoked via a qrexec call? If so, I'd love to see an example. Thanks.