First step would be import csv with DL names which you would like to check
$List=import-csv “C:\Users\username\Desktop\DLs.csv”
Second would to find the managedby for those DL’s
ForEach ($User in $List){Get-DistributionGroup -Identity $User.name| select name,Managedby | out-gridview}… Read the rest
First lets get the list of users samaccountnames from Distribution list
$List=Get-ADGroupmember DistributionlistName
Now create a empty Security group from Active Directory Users and Computers
Now lets add each of above user into a security group which is created from ADUC(Active Directory Users and Computers).
ForEach ($User in $List){Add-ADGroupMember -Identity SecurityGroupName -Member $User.samaccountname}
We can also use add members to distribution group powershell by this method of Add-ADGroupmember
We can also use powershell to add members to distribution group powershell or a Security group.