[Lunia] HKN is sending keys but no response in-game?

I'm a multi-boxing newbie, so I'm a bit confused about what is going wrong here.. I'm trying to multi-client an older game called Lunia. I usually run all instances through Sandboxie.
I've succeeded in making a script that creates a few hotkeys to control two instances on one system, and can confirm that the input is getting sent to the correct windows since keypresses are getting sent and registering in the in-game chatbox, but if the chatbox is not active, there is no reaction in either instance.

Code:

---

<hotkey lctrl numpadminus>
<sendpc local>
<renamewin Lunia Lunia01>
<renamewin Lunia Lunia02>


<Label L1 local sendwinm Lunia01>
<Label L2 local sendwinm Lunia02>


<MovementHotKey up, down, left, right>
<sendlabel L1, L2>
<key %trigger%>


<Hotkey A, S, X, Q, W, E, R, T, Y, 0-9, F1-F10>
<sendpc local>
<sendwinmf Lunia01>
<key %TRIGGER%>
<sendwinmf Lunia02>
<key %TRIGGER%>

---

I've tried all the variations for sendwin and all of them are showing the same behavior. Is there a way to send ASCII/Unicode codes to a program instead of keystrokes? Or someway to determine what type of input the game is looking for? Or is my script perfectly fine and it's an issue related to running through a sandbox? Any and all help/advice is welcome and appreciated. ^^

Many games filter out input when the game window is inactive. This would include things sent by key/mouse broadcasting software like HotkeyNet and Keyclone, and may be the issue here with Lunia.

If it is, then you'll have to specifically activate each game window instance in your HKN script as you're sending keys. I'm not familiar with how to do that with HKN.

ISBoxer on the other hand eliminates the issue with a check box "Make game believe it is foreground window".

Thanks for the quick reply! ^^

The problem is there regardless of whether or not either window has current focus.
Both instances are accepting the keystrokes in the chatbox even when neither are the current focus.
(ex: Two Lunias running with chatboxes open, I open up a new .txt file and hit the "a" key - "a" shows up in the new text file and both Lunia chatboxes.)
That tells me that HKN is doing what it should be doing and winsendm is functioning correctly, so my uneducated guess would be that the program is expecting some other signal rather than the raw keystroke? It's a Korean MMO which has official clients in something like seven languages, which is why I asked about possible Unicode/ASCII output from HKN since I would think that would be easier for the devs to deal with international keyboards. I am just really hoping that it's not looking for DirectInput since dealing with that seems to involve me learning how to program and I am usually too medicated to handle any heavy thinking/memorization. ~_~