Registering in custom event log (C # app, but using win32 API)

Due to a limitation in the .NET EventLog class, I have code that uses PInvoke that gets logged in the application log. The code works without issue.

But now I want to register in the event log. So I tried to change the second parameter of RegisterEventSource to "companyX" (my own log). It wrote correctly in "companyX" (instead of the application log), but it also set the Source field (of the individual log entry) to "companyX", which is not what I want.

So how do I change my code to:

• Use the new, custom event log ("companyX"), but also
• Use correct original value ("MyApp")

Currently it either writes to the application log correctly (with the correct original value "MyApp") or writes to the event log ("companyX") and uses the wrong Initial value (not "MyApp", it sets the Source value to "companyX" , custom log name).

EDIT: Please note that the "companyX" log has already been created (in the WIX installer code).

Here's my code:

private void WriteEntryToLog(string msg, LogEventType entryType)
{
    // ApplicationName = "MyApp"
    // The code as-is is writing to the Application log. Changing the 2nd param of
    // the function below to "companyX" allows me to write to my "companyX" event log,
    // but also changes the Source value of each entry append to that log to "companyX" rather than "MyApp"
    IntPtr eventSrcHandle = NativeMethods.RegisterEventSource(null, Resources.ApplicationName);


    try
    {
        uint tokenInfoSize = 0;
        IntPtr userTokenPtr = WindowsIdentity.GetCurrent().Token;
        const UInt16 typeError = 1, typeWarning = 2, typeInformation = 4;

        //using this first call, get the length required to hold the token information in the tokenInfoSize parameter
        bool bresult = NativeMethods.GetTokenInformation(userTokenPtr, NativeMethods.TOKEN_INFORMATION_CLASS.TokenUser, IntPtr.Zero, tokenInfoSize, out tokenInfoSize);
        if (bresult) throw new Win32Exception(Marshal.GetLastWin32Error());

        IntPtr userTokenInfo = Marshal.AllocHGlobal((int)tokenInfoSize);
        try
        {
            //get the user token now with the pointer allocated to the right size
            bresult = NativeMethods.GetTokenInformation(userTokenPtr, NativeMethods.TOKEN_INFORMATION_CLASS.TokenUser, userTokenInfo, tokenInfoSize, out tokenInfoSize);
            if (!bresult) throw new Win32Exception(Marshal.GetLastWin32Error());

            UInt16 type = typeError;
            switch (entryType)
            {
                case LogEventType.Error:
                    type = typeError; 
                    break;
                case LogEventType.Warning:
                    type = typeWarning; 
                    break;
                case LogEventType.Information:
                    type = typeInformation; 
                    break;
                    default: 
                        type = typeInformation; 
                        break;
            }

            NativeMethods.TOKEN_USER tokUser = (NativeMethods.TOKEN_USER)Marshal.PtrToStructure(userTokenInfo, typeof(NativeMethods.TOKEN_USER));

            string[] message = new string[1];
            message[0] = msg;
            bresult = NativeMethods.ReportEvent(eventSrcHandle, type, 0, 0, tokUser.User.Sid, 1, 0, message, new byte());
            if (!bresult) throw new Win32Exception(Marshal.GetLastWin32Error());
        }
        finally
        {
            Marshal.FreeHGlobal(userTokenInfo);
        }
    }
    finally
    {
        NativeMethods.DeregisterEventSource(eventSrcHandle);
    }

      

        
        
        
      

    

}

Oh, and this is not a repetition of the question here: Custom value for event log source property for ASP.NET errors since I have to use PInvoke for that. =)