Sequence no. creation automation using formula

[Pratichi]

Hi guy,
Need some help with sequence creation.
We have a task list with 4 levels of Tasks
I want to generate a sequence such that 

Level	Sequence Start
Lvl 1	1
Lvl 2	1.1
Lvl 3	1.1.1
Lvl 4	1.1.1.1

I've attached a sample file, but I would like to know if anyone has done something like this before.
the sequence should also stop when the level changes... ie .

Task level	Sequence Start
Lvl 1	1
Lvl 2	1.1
Lvl 3	1.1.1
Lvl 4	1.1.1.1
Lvl 4	1.1.1.2
Lvl 4	1.1.1.3
Lvl 2	1.2
Lvl 3	1.2.1
Lvl 4	1.2.1.1

[#2]

@Pratichi 

In C7:

="Lvl "&LEN(D7)-LEN(SUBSTITUTE(D7,".",""))+1

Fill down.

[#3]

I actually want it the other way... ie i know the level, I need a formula to give me the sequence. :(

[#4]

@Pratichi 

But your workbook already has the 1.1 etc. but not the levels...

[#5]

What you're looking to do is possible with clever use of SEQUENCE. I'm not trying to dissuade you from using Excel, but you may want to consider MS Word for this task. Word can produce the multi-level list you're looking to use without much legwork.