- You will need to go to Youtube
- Go to your video
- Below the video there is a "SHARE" button

- Use the EMBED link. This will look like this:

<iframe width="560" height="315" src="https://www.youtube.com/embed/m7rO-lC2ZEM" frameborder="0" allowfullscreen></iframe>
- Change the "width="560" to width="320"

- Go to  https://www.opinionatedgeek.com/DotNet/Tools/HTMLEncode/Encode.aspx

- Paste the EMBED url in it en press "encode"

- You can paste this url in your Excel sheet.

To show it in your template, click on "source" and paste:
- <webview field="video" margin="10" width="fill_parent" height="200" /> 

(where "video" is the column name of your Excel where you have to url to the video)