Sending Windows key combos?

[UTAN_dev]

I'm connecting from a Windows 10 client PC to a tightvncserver session on a laptop running Linux Mint. I want to be able to send Windows+(some_key) combos to the server (e.g. Windows+Left). On the client, the Windows key is mapped to mod4 and mod4+Left is defined. (It tiles the window to the left half of the screen.)

Even when I have ScrollLock active on the client, Windows key combos don't seem to work:

• If I press Windows+L, the combo is not captured by UltraVNC and I go to the Windows lock screen.

• If I press Windows+Left, only the Windows key (i.e. mod4) is sent to the server.

How can I get Windows key combos to work correctly? Thanks!