How to print/output array in a tab-delimited format?

I create an array and print it to a file as such:

(setf arr #2A((1 2 3) (4 5 6) (7 8 9)))
(setf out-stream (open "Output.txt" :direction :output))
(print arr out-stream)
(close out-stream)

But the output is in the CL array form. Is there a way to print the
array's columns and rows in a tab-delimited format that can be
immediadely read as a spread*** by something like MS-Excel? Thanks
.