static extern IntPtr OpenEventLog(string UNCServerName, string sourceName);

        IntPtr logHandle = OpenEventLog(Environment.MachineName, eventLogName);

hEventLog is the handle for the log you wish to operate on, this handle can be got from OpenEventLog if needed.

        hEventLog = NativeMethods.OpenEventLog(IntPtr.Zero, logName);

    static extern IntPtr OpenEventLog(string UNCServerName, string sourceName);

Declare Function OpenEventLog Lib "advapi32.dll" (TODO) As TODO

IntPtr logHandle = OpenEventLog(Environment.MachineName, eventlogName);