Thank you very much Carl for your reply and patience. Yes, I am a bit more inclined to LotusScript rather than Java.
Thanks for that link of code in Java agent & LS too. I modified my code and it works. So, IT IS possible to read an attachment in LS without extracting it.
Also, I came across other ways using DXL and even NotesDOMparser.
DXL method:
http://www-10.lotus.com/ldd/nd6forum.nsf/55c38d716d632d9b8525689b005ba1c0/447b2cf2af3d3f28852572580068eade?OpenDocument
NotesDOMParser method:
http://www-10.lotus.com/ldd/nd6forum.nsf/55c38d716d632d9b8525689b005ba1c0/8e96e1a798bf8e5a852571830006f0ae?OpenDocument&Highlight=0,read,stream,from,attachment
I am sure others will find these helpful when they want to read an attachment without extracting it.