Import Equities and Cost Basis from Excel to a Portfolio

I would like to be able to upload data like ticker symbol, cost basis, date purchased from an Excel spreadsheet into a Seeking Alpha portfolio. I can do this in the basic version of Yahoo Finance. I know I can link my brokerage to Seeking Alpha but I tried that once and it caused me to get locked out of my account due to what appeared to my broker as unauthorized logins. So I don't want to do that. Ultimately I would like to export from my brokerage to a .csv file, format it in whatever way Seeking Alpha would want then upload to portfolios with cost basis and purchase date at minimum.