How to run powershell cmdlets one after the other - powershell

Question

I have a sharepoint 2010 list designed with custom solution. It has 3 level folder hierarchy. In the last folder level multiple documents are present as attachments. I want to get all the document attachments from that folder and store it in my local drive, so that it can be migrated to a different platform.
Number of Attachments are around 350000.
My Tasks are:
Creating Folder in my drive.
Getting Attachment ids and create folder with id name, as inputs from a txt file.
Map network drive
Copy attachment from network drive to local folder.
Delete network drive.
These 5 steps are to be repeated for around 350000 attachments.
Kindly let me know if cmdlets can be executed properly one after the other.
$idsFile = "H:\D\Temp\testingid.txt"
$FileStore = "H:\D\Temp\Attachments"
foreach ($line in Get-Content $idsFile) {
$FileCount = 1
$thisappid = $line.Split("`t")
Write-Host $thisappid.GetValue(0)
$FPath = $FileStore + '/' + $thisappid.GetValue(1)
Write-Host $FPath
if (!(Test-Path $FPath)) {
Write-Host "Creating folder.."
$F1 = New-Item -Path $FileStore -Name $thisappid.GetValue(1) -ItemType "directory"
Write-Host $F1
$F2 = New-Item -Path $F1 -Name $thisappid.GetValue(0) -ItemType "directory"
} else {
Write-Host "Folder" $thisappid.GetValue(1) "Already exists"
$SPath = $FileStore + '/' + $thisappid.GetValue(1) + '/' + $thisappid.GetValue(0)
Write-Host $SPath
if (!(Test-Path $SPath)) {
$F2 = New-Item -Path $SPath -Name $thisappid.GetValue(0) -ItemType "directory"
Write-Host $F2
} else {
Write-Host "Folder" $thisappid.GetValue(0) "already exists"
Write-Host "Move to Next.."
}
}
Write-Host $thisappid.GetValue(0)
$id = $thisappid.GetValue(0) -as [int]
Write-Host $id
Write-Host $id.GetType()
net use Y: \\domainName/sites/SiteName/Lists/MyList/Attachments/$id
/Persistent:Yes
Start-Sleep -s 10
$name = Get-ChildItem -Path Y:\ -Name
Start-Sleep -s 10
Copy-Item -Path Y:\$name -Destination $dest
Start-Sleep -s 10
net use Y: /delete /y
Start-Sleep -s 10
$FileCount = $FileCount+1
Write-Host $FileCount
}