Enter-Using-Excel.ps1

function Enter-Using-Undisposable($receiver, [scriptblock]$body, [scriptblock]$finally) {
	try {
		return $receiver | % { & $body }
	}
	finally {
		& $finally
	}
}

function Enter-Using-Excel([scriptblock]$block) {
	$excel = New-Object -ComObject Excel.Application

	Enter-Using-Undisposable $excel $block {  
		[Runtime.Interopservices.Marshal]::ReleaseComObject($excel) | out-null
	}
}

sample.ps1

Enter-Using-Excel {
	$_.LargeOperationCellThousandCount
}