>Under the menu command "Format - Numbering...", you can select a multi-level numbering scheme. I guess you could include this as part of the style definition. However, the numbers are placed to the left, not to the right as in your example.

Yes, you are right. It should be placed on the left.

>You have more flexibility - and more work - if you use auto-numbering fields. It seems the appropriate field, in this case, is LISTNUM. Unfortunately, you have to manually insert it into each and every header. More information on LISTNUM here: http://support.microsoft.com/kb/162895/en-us/

By using the style, I was able to find the numbering options. This works for my Header1 style. For every chapter, I have 1, 2, 3 and so on. But, I haven't found an option would allow me to have the sub styles to include the parent representation in its number. For example, if I have two sections for Header2 under Header1, they will be 1, 2, 3 and so on no matter if I change chapter (by the use of Header1). So, they will not restart at 1. And, as mentioned, they do not include the parent representation.

So, I end up with:

1. This is title for Header1 style
   1.  This is title for Header2 style
   2. This is title for Header2 style
2. This is title for Header1 style
   1.  This is title for Header2 style
   2. This is title for Header2 style
3. This is title for Header1 style
4. This is title for Header1 style

instead of:

1. This is title for Header1 style
   1.1.  This is title for Header2 style
   1.2. This is title for Header2 style
2. This is title for Header1 style
   2.1.  This is title for Header2 style
   2.2. This is title for Header2 style
3. This is title for Header1 style
4. This is title for Header1 style