$list = Get-Content "dg.txt"

Foreach ($i in $list) {
$i
$grp = get-distributiongroup $i
$manage = $grp.managedby
$newuser = get-user k.tsvetkova
$newmanage = $manage + $newuser
Set-distributiongroup $grp -managedby $newmanage -bypasssecuritygroupmanagercheck
}

Вид файла CSV:

#user,#groupname 


#$list = import-csv AddDistributionGroupOwnerList.csv

#Foreach ($i in $list) {
# $grp = get-distributiongroup $i.groupname
# $manage = $grp.managedby
# $newuser = get-user $i.user
# $newmanage = $manage+$newuser
# Set-distributiongroup $grp -managedby $newmanage -bypasssecuritygroupmanagercheck
#}