Solution: What to do if your mouse does not lock to the game in a multi-monitor setup.
I recently bought C&C: Red Alert 3 and I'm liking it so far. However my mouse does not lock to the game-window using dual monitors.
Since this is a problem with many games in a multi-monitor setup I have written a small program to confine the cursor to the boundaries of the primary monitor (e.g. "clip the cursor").
It is written in VB6 and will run on any PC sporting Windows XP or newer. Since it is VB6 (no .net-Shamework here), it uses hardly any memory or cpu time.
I guarantee that it is free of malware, spyware or viruses (and of charge for that matter ;]). No installation, just unzip and run:http://s382701517.online.de/apps/PrimaryLock.zip
As long as it is running, you can not move the cursor out of your primary display device. The effect ends after you close the window. What it does is to simply (ab)use the Windows API-function ClipCursor which can be used to keep the cursor inside a given rectangle on the desktop.
I first created this for TES V: Skyrim, but it should work with almost all Steam-games (e.g. tested with Magic DotP 2012, Puzzle Quest 2, Batman Arkham City and many more) and therefore with Red Alert 3, too of course... :)
The current version only supports games that run on the monitor's native resolution, if the in-game resolution is higher, you can not move the mouse over the whole screen, if in-game resolution is lower, it basically has no effect.
Hope it works for you, enjoy and comment... :)
Regards from Munich, Germany