With reference to the tip Mass load for multiple selection sent in by Satish Natarajan on 04 Feb 2004.
He wrote,"Ever wondered how to paste the huge list of object numbers into the selection option screen? Up to R/3 version 4.5B, users were forced to manually copy and paste seven items at a time with page down and repeat this over and over until their nails broke. Well not anymore, from 4.6 onwards you can load data from file and avoid the pain. Simply use the Green comment icon (2nd from right)"Import from text file" to do the above."
There is more. After clicking on the "Import from text file" button there is another button "Upload from clipboard" that uses the copy and paste windows functionallity to insert the object selection. This saves first creating a text file.