using LogQuery = Interop.MSUtil.LogQueryClassClass;
using IISInputFormat = Interop.MSUtil.COMIISW3CInputContextClassClass;
using LogRecordSet = Interop.MSUtil.ILogRecordset;

LogQuery oLogQuery = new LogQuery();
IISInputFormat oIISInputFormat = new IISInputFormat();
string query = @"SELECT COUNT(DISTINCT c-ip) AS hits
                 FROM 'C:\WINDOWS\system32\Logfiles\W3SVC1\ex070820.log'
                 WHERE cs-uri-stem like '%.asp'
                 AND sc-status=200";
LogRecordSet oRecordSet = oLogQuery.Execute(query, oIISInputFormat);
if (!oRecordSet.atEnd())
{
    hits = (int)oRecordSet.getRecord().getValue("hits");
}
oRecordSet.close();