We cannot teach you how to use Powershell. You should take a little time and learn the basics of Powershell at least.
Some good starting points you can find here: Beginner Sites and Tutorials
I know the basics of Powershell but the problem was it doesnt take the built of 3 different fields.
becouse from one collum it needs to take the username of the mailbox that i want to see who have access
one collum is the user that needs access to the mailbox
and the third collum is for the access rights
hmmm ...are you really sure? ;-) ... usually my next question would be "What did you try so far? Show your code and the errors you get". ;-)
It’s slightly easier to get the data you need from a csv file than from an Excel sheet. You can use Import-CSV and loop over all the contained data sets. If you have 3 columns with the header Mailbox, account and access you could start with this:
Import-Csv -Path YourCSVFileIncludingPath.csv -Delimiter ‘,’ | ForEach-Object {
#
# here you place your code with whatever you want to do
# you can access the single properties with “subexpressions”
# to the Pipeline variable
$.Mailbox
$.Account
$_.Access
}