Hmm. No need to bang your head. Not sure why you didn't try my suggestion. It is exactly what you need.
Maybe this will help:
function Get-NameFromDN([string]$DN){
return ($DN.replace('\','') -split ",*..=")[1]
}
Get-QADMemberOf $user -Indirect | ft Name,@{n="ManagedBy";e={Get-NameFromDN $_.ManagedBy}}
If you don't like that then try this:
Get-QADMemberOf $user -Indirect | ft Name,@{n="ManagedBy";e={($_.ManagedBy -split ",*..=")[1]}}
The link to my post earlier explained how the -Split works. -split will use [regex] as delimiters.