powershell windows form Expert

Overview- My requirement is import data from excelsheet into datagridview and export custom data from excelshet to text and csv file using powershell script

Details: Need to pickup the selected excelsheet. Import the data from choosen sheet into datagridview. The excel sheet contains 20 columns. Based on the filter only selected columns data need to be exported into .txt and .csv file. While export the data the columns named need to be modified.