# Load Microsoft.Office.Interop.Excel assembly
Add-Type -AssemblyName Microsoft.Office.Interop.Excel

# エクセルを開く
$excel = New-Object -ComObject Excel.Application

# ブックを開く
$workbook = $excel.Workbooks.Open("C:\\file.xlsx")

# シート取得
$worksheet = $workbook.Worksheets.Item(1)

# セル取得
$usedRange = $worksheet.UsedRange

# ２次元配列取得
$data = $usedRange.Value2

# 見出し取得
$headers = $data[0]

# データから見出し削除
$data = $data[1..($data.Length-1)]

# DataTable作成
$dataTable = New-Object System.Data.DataTable

# DataTableに見出し作成
$dataTable.Columns.AddRange($headers | ForEach-Object { New-Object System.Data.DataColumn $_ })

# DataTableにデータ入力
$data | ForEach-Object { $dataTable.Rows.Add($_) }

# Clean up
$excel.Quit()
[System.Runtime.Interopservices.Marshal]::ReleaseComObject($excel)

# Use the System.Data.DataTable
$dataTable