Put part of Filename in line 8 - powershell

Question

I habe some files, they are all named after the same scheme (Wien - Number - Text, e.g. Wien - 001 - Text, Wien - 002 - Text). The files are nfo.
They have nfo files, but they are not correct, I was able to delete the wrong entry with advanced renamer.
Now I want to put the Number in line 8 of the nfo file.
I got this to work with only one file but I have several files in one folder and I haven't got this to work.
Here is my script
Get-ChildItem -Filter "*.nfo" | Foreach-Object{
$baseName = $_.BaseName
$array = $baseName -Split ' - '
$addToFile = '<episode>' + $array[1] + '</episode>'
$filePath = ".\*.nfo"
$fileContent = Get-Content $filePath
$lineNumber = "8"
$textToAdd = $addToFile
$fileContent[$lineNumber-1] = $textToAdd
$fileContent | Set-Content $filePath
}

Answer 1

As Bacon Bits already commented, you're not using the ful path and filename of the file where you already have that in $_.FullName.
Also, you could do with a lot less 'in-between' variables.
Try
$lineNumber = 8
Get-ChildItem -Path 'X:\WhereTheFilesAre' -Filter "* - *.nfo" | Foreach-Object {
$fileContent = Get-Content -Path $_.FullName
$fileContent[$lineNumber-1] = '<episode>{0}</episode>' -f ($_.BaseName -split ' - ')[1]
$fileContent | Set-Content $_.FullName
}
'<episode>{0}</episode>' -f ($_.BaseName -split ' - ')[1] is a very nice way to create a new string using the Format operator