Text to .xls With Formatting

Text to .xls With Formatting

Is there a way to write out in a text editor format cell a1 bold and set
the contents of that cell and then save the file in .xls or any excel
format? I also need to set the color of the font as well or the background
color of the cell.
I feel like this is a bit of a long shot but for a very odd reason I need
to be able to do this manually.