The first task is to save the Word file as a web page. Remember: when you save a Word document as a web page, make sure you choose "Web Page, Filtered" from the list of Save as type options.

If you aren't there already, go to your course front page, find the course Administration block and click on Files. Upload to Moodle the page you have just saved. It might be an idea to first create a folder in your course files area that you can upload to. This file will be your wiki template.

Now return to your course front page (either via the breadcrumb trail at the top of the page, or the button at the bottom if you have one) and click on the Update icon next to your wiki.

Scroll down to the Optional box. Make sure the Advanced settings are visible. You might need to press the Show Advanced button if the Optional box is empty. You should see a setting called Choose an initial page: