Exporting the Excel worksheet back out to the RTF format should be easy enough, using a formula that reads all the values in columns A through E and generates a character string in a separate worksheet which you then save. Or for that matter you can just cut-and-paste that export column of text to Notepad and save it with an RTF extension.

Importing the RTF to Excel would be a little more complicated, using formulae. Personally I use VBA at the drop of a hat, and you might find it easier too. But it can be done with worksheet functions, if you don't mind a lot of helping columns at the right. At least, I'm pretty sure it can. Do you have a preference as to which, formulae or VBA?

The formula method would probably involve you opening the RTF document, then cutting and pasting the text into an Excel column. (It might not, though; I'd want to start by asking you how you got that text into Excel.) The VBA method would be more complex to write, unless of course you like that sort of thing—but it would work faster, and would probably be able to go get the data from the source document itself.