Need excel specialist to make formulas

Job ID: 31139100

Budget: $10 – $30 CAD

I have a CBS breakdown that follows this coding structure

1
1.1
1.1.1
1.1.1.1

And I need excel to take out a level. If it is 1 then its level 1. if it is 1.1 then it is level 2. and so on