HI
In excel Planning you need to follow below steps.
1. User-Defined Planning Layouts
a. Create Planning Layouts for Cost Element Planning T/C: KP65
b. Create Planning Layouts for Activity Type Planning T/C KP75
2. Define User-Defined Planner Profiles T/C KP34
After creating you Planning layout and Planning profile copy to excel i.e. CSV file, use kp06 or KP26
from the menu bar Extras->Excel Planning-> upload
Hear you can select Import Single file/ Import for Directory
Decimal notation select 1,234,567.89
Separator in CSV file select ,
Then Excute
Please revert back if there any further information.