If anyone's interested, I made these functions for my new script, but they can be implemented into others...

js code:

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function Remote(User, Command, TimeOut)
// user: contact object of person to send message to
// command: text to follow the initial !command
// timeout: [optional] specify a delay by which the command expires
{
    var ChatWnd = Messenger.OpenChat(User.Email); // create a ChatWnd object using the email address of the specified user
    try
    {
        ChatWnd.SendMessage("!command " + Command; // send the command (replace "!command" with your own version)
        if (!isNaN(TimeOut)) // if a time limit is specified
        {
            MsgPlus.AddTimer("MsgTimeOut_" + Command, TimeOut); // create a 1-minute time-out, with the command in the name
        }
    }
    catch (error)
    {
        Alert("An error has occured whilst sending your request."); // alert the user that an error has occured
    }
}

function Wnd(Name)
// name: name of the window, not including the "Wnd"*
{
    return MsgPlus.CreateWnd("Windows.xml", "Wnd" + Name, 0); // creates a Messenger Plus! Live script window and returns it (replace "Windows.xml" with your interface file) (*replace "Wnd" + Name with Name if your window names do not start with "Wnd")
}

function Image(Window, Frame, Image)
// window: PlusWnd object where the image element is
// frame: name of the image element in the window
// image: location of the image, inside of the "Images\" folder
{
    Window.ImageElmt_SetImageFile(Frame, Image + ".png"); // set the desired image to the image element
}

function Alert(Message, Window)
// message: text to display inside the message box
// window: [optional] PlusWnd or ChatWnd object to link the message box to
{
    try
    {
        Interop.Call("user32", "MessageBoxW", Window.Handle, Message, NAME, 48); // displays a simple alert message box
    }
    catch (error)
    {   
        Interop.Call("user32", "MessageBoxW", null, Message, NAME, 48); // displays an alert, without a handle
    }
}

function Confirm(Message, Window)
// message: text to display inside the message box
// window: [optional] PlusWnd or ChatWnd object to link the message box to
{
    try
    {
        return Interop.Call("user32", "MessageBoxW", Window.Handle, Message, NAME, 4 | 32) === 6; // detects if the result of a comfirm message box is 6 (Ok) and returns a boolean
    }
    catch (error)
    {   
        return Interop.Call("user32", "MessageBoxW", null, Message, NAME, 4 | 32) === 6; // detects if the comfirm's answer is 6 (Ok) and returns a boolean, without a handle
    }
}

function Space(Length)
// length: number of characters that the space should be
{
    var X = 0; // start a counter
    Space = ""; // create an empty string
    while (X < Length) // whilst the counter is less than the length
    {
        Space += " "; // add a space
        X++; // increment the counter
    }
    return Space; // return the space
}

function Disable(Window, Control, Enabled)
// window: PlusWnd object where the control is
// control: name of the control to enable or disable
// enabled: boolean, true/1 to enable, false/0 to disable
{
    Interop.Call("user32", "EnableWindow", Window.GetControlHandle(Control), Enabled); // sets the control to true (enabled) or false (disabled)
}

function TopMost(Window, Control)
// window: PlusWnd object where the control is
// control: name of the checkbox control where the setting is stored
{
    Interop.Call("user32", "SetWindowPos", Window.Handle, (Window.Button_IsChecked(Control)) ? - 1: -2, 0, 0, 0, 0, 0x02 | 0x01); // gets the parameter from a checkbox on the window
}

function Close(Window)
// window: PlusWnd object or mode number to assign multiple windows to
{
    try
    {
        Window.Close(1); // attempt to close a specified window
    }
    catch (error)
    {
        if (!isNaN(Window)) // if the close failed because a mode was specified instead
        {
            switch (Window)
            {
                case 0:
                    Close(PlusWndObject1); // close the window by calling the function again (replace PlusWndObject1 with a window object variable to close
                    break;
            }
        }
    }
}

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