drop last line of each file processed

  Is there a way as i;m processing files can I drop the last line of each file before I write it? The last record in each of files I process is a total record
which I don't want to include in my final file. The script process thru multiple folders and rolls all the data to a single file. I just need to drop
the last record before appending to my file. sistem.csv is the single file created. The last record in each of the files always has a record starting
with $z or $Z. I have a parm file that I pass to script that has PATH and a shortname.

D:\AreaSistemi1\folder1~e10
D:\AreaSistemi1\folder2~e13

*.spx files in folder1 and folder2 look like this:
E200,%s001,&d000
E200,%s001,&d000
E200,%s001,&d000
$z,0,9,0

 Before I write is to sistem.csv I want to not write the last record in each of the files.

param
(
  [string]$path
)
$myFiles = Import-Csv -Delimiter '~' -Path $path -Header Path, ShortName
# Then you can call it like so
$myFiles.Path #Returns just the path
$myFiles.ShortName # Returns the shortname
$path='D:\AreaSistemi1\'
foreach ($myFile in $myFiles)
{
	get-childitem -path $myFile.Path *.spx | % {" Starting File Process....."  >> $myFile.Pathsistem.log
	   $PDate = get-date
       $date = get-date -uformat "_%d_%m_%Y_%H%M%S.bak"
       #"Set backup date to $date" >> $path\sistem.log
       $newname=($_.fullname -replace ".spx",$date)
	   $file = [System.IO.Path]::GetFileNameWithoutExtension($_.fullname)"File backup name is $newname" >> $myFile.Pathsistem.log 
       Rename-Item $_.fullname $newname"Renamed file to $newname" >> $myFile.Pathsistem.log
	   $lines = get-content $newname
	   foreach ($line in $lines) 
	    {
			$line + " " + $myFile.ShortName  | Out-File "$path\sistem.csv"   -append
	    }		
       Write-Host $_.fullname "Files Processed on $PDate are $newname " >> $path\sistem.log
	}
}

# .\newload.ps1 c:\AreaSistemi1\AreaSistemi.txt >> Runlog.txt