I have a document with a list in it, and a second one also with a numbered list

When I select copy in the second list, and then paste into the main document, I want the list to be copied into the main document, with the numbering and style matching the list in the original document - the numbering continuation from the list above!

e.g See below

Main document
1 Heading
1.1 this is para 1
1.2 this ios ppara 2

2. Heding
2.1 etc
2.2 etc

In the second document it dos
1 Heading
1.1 this is para 1 from doc 2
1.2 this ios ppara 2 from doc 2

2. Heding
2.1 etc doc 2
2.2 etc doc 2


When I copy and past I want it to read
1 Heading
1.1 this is para 1
1.2 this ios ppara 2

2. Heding
2.1 etc
2.2 etc


3 Heading
3.1 this is para 1 from doc 2
3..2 this ios ppara 2 from doc 2

4. Heding
4.1 etc doc 2
4.2 etc doc 2

Any ideas?