I need to develop an automated method for adding period-delimited
hierarchical numbering of cells. The pattern would be something like:

1.0
....
1.1
1.1.1
....
1.2
1.2.1
1.2.1.1
1.2.1.2
1.2.1.3
1.2.1.3.1
1.2.1.3.2
1.2.1.3.2.1
....
2.0
....
2.1
2.1.1
2.1.2
2.1.2.1
2.1.2.2

etc

how can I do this for and unlimited number of rows? I don't see a standard
format for this.

Thanks for suggestions

Dave G.