Append response from Get-MsolSubscription into a csv file in the desktop. Call Connect-MsolService before running this.

Log-MsolSubscription.ps1

function Log-MsolSubscription
{
    begin
    {
        $timestamp = Get-Date -format "yyyyMMddHHmmss"
        $executionName = $MyInvocation.MyCommand
        $logFilename = "$($timestamp)_$(gc env:computername)_$($executionName)"
        $logPath = "$([Environment]::GetFolderPath("Desktop"))\$executionName\$logFilename.log"
        Start-Transcript -Path $logPath > $null
    }

    process
    {
        $datetime = Get-Date -format 'dd-MMM-yyyy H:mm:ss'
        $csvPath = "$([Environment]::GetFolderPath("Desktop"))\$executionName.csv"
        $initialDomain = (Get-MsolCompanyInformation).InitialDomain

        $report = Get-MsolSubscription | %{
            [pscustomobject] @{
                CreatedBy = gc env:computername
                Created = $datetime
                InitialDomain = $initialDomain
                SkuPartNumber = $_.SkuPartNumber
                TotalLicenses = $_.TotalLicenses
            }
        }
        
        $report | fl *
    }

    end
    {
        $report | Export-Csv $csvPath -NoTypeInformation -Append
        Stop-Transcript > $null
    }
}

Log-MsolSubscription