HOWTO combine multiple text files into one excel spreadsheet powershell

I' am a new in Power Shell world and i need to create a poweshell script which combine multiple text files into one excel spreadsheet With PowerShell  is it possible?  

1 – Convert text files .txt TO .csv or .xls  Does anyone can help me?

All I need to do is to convert/combine multiple text files into one excel spreadsheet

Combine multiple .txt files into one CSV spreadsheet