Multilevel lists - Document starting with second level

[thara]

I want to create a word document in MS Word 2007 with numbering starting from second level and proceeds upto fourth level. I don't want first level and second level numbering should start from 6.6.

6.6. Storing & Exchange of data requirements

6.6.1. Storing of data to External medium
6.6.1.1. Description
6.6.1.2.Inputs
6.6.1.3. Process
6.6.1.4. Outputs

6.6.2. Importing data from external storage
6.6.2.1. Description
6.6.2.2.Inputs
6.6.2.3. Process
6.6.2.4. Outputs

6.7. Filming requirements


6.7.1. Transfer Images to Film
6.7.1.1. Description
6.7.1.2.Inputs
6.7.1.3. Process
6.7.1.4. Outputs

Should I define a new multilevel format or can it be done by modifying existing format?

Thanks