Rewriting of ConvertFrom-Csv, as an exercise. Quickly done and unfinished.

ConvertFrom-Csave.ps1

Function ConvertFrom-Csave {
    [CmdletBinding(DefaultParameterSetName='UseDelimiter')] 
    Param (
        [Parameter(Position=2,ParameterSetName='UseDelimiter')]
        [char]$Delimiter = ',',
        # FIXME
        [string[]] $Header,
        [Parameter(Mandatory=$True,Position=1,ValueFromPipeline=$True,ValueFromPipelineByPropertyName=$true)]
        [PSObject] $InputObject,
        [Parameter(Mandatory=$True,Position=2,ParameterSetName='UseCulture')]
        [switch] $UseCulture
    )
    Begin {
        $OutputObject = New-Object PSCustomObject
        $HeadersDone = $false
        $Properties = @()
        If ( $UseCulture ) { $Delimiter = (Get-Culture).TextInfo.ListSeparator }
    }
    Process {
        If ( $InputObject -like '#TYPE *') {
            $OutputObject.pstypenames.insert(0,'CSV:' + $InputObject.ToString().Replace('#TYPE ',''))
        } ElseIf ( !$HeadersDone ) {
            foreach ( $Property in $InputObject.Split($Delimiter) ) {
                $Properties += $property -Replace('^"(.*)"$', '$1')
                Add-Member -InputObject $OutputObject -MemberType NoteProperty -Name ($property -Replace('^"(.*)"$', '$1')) -Value ""
            }
            $HeadersDone = $True
        } else {
            $i = 0
            foreach ( $Property in $InputObject.Split($Delimiter) ) {
                $OutputObject."$($Properties[$i])" = $property -Replace('^"(.*)"$', '$1')
                $i++
            }
            $OutputObject
        }
    }
}