How hard would be be to create a macro (more modify an existing one you know off) that will add a custom property ie Item #, to all the assembly & parts in a solidworks assembly.

Eg

Assm 1                          Item # 1
Assm 1 sub part 1       Item # 1.1
Assm 1 sub part 2       Item # 1.2

Part A                            Item # 2
Part B                            Item # 3

Etc

Also ability to add this information to a parts different configurations used in the assembly would be great.

Any help you can give me would be great