I understand what a drop cap is. You cannot do this using the fonts available in the command window.

However you can do something fairly crude like this in a batch file
echo.
echo ######
echo # #
echo # ri
echo ######
echo # oftware
echo # #
echo ######
echo.
or this
echo.
echo @@@@@@
echo @ @
echo @ ri
echo @@@@@@
echo @ oftware
echo @ @
echo @@@@@@
echo.
If you have a text editor with search/replace it is easy to try different characters like x, * @, # or whatever you want. it will be a lot easier (!) to visualise the final result if you set the editor to use monospaced fonts such as Courier New or Lucida Console.