C# 2008 app

Question

In a C# 2008 console application, the code currently shows the commands to run the console application in one dos window. The application also has a popup dos window that shows the results on each application  run. Basically for each time the console application is executed, a new dos window shows up.
 Now my questions are the following:
1. For the commands to run the console application, can you show me how to write these results to one log file?
2. For the results of executing the console application, can you show me how to write these records out to another log file. I want all the log results to go to one file. I do not want a log record written for each individual run.