create block with N last entity

Hi

I'm starting making lisp program.

I have to make a LISP to draw N line and put it in a block at the same place off my original line.

I know how to make line in a LOOP, but not how to select the N last entity and make a COPYBASE, ERASE "Previous", PASTE AS A BLOCK " previous"

Someone can help with that.

Excuse my english, i'm a french boy.

for every loop you can "capture" the last entity by using (entlast) function

(seqt asdf (ssadd))
(while doing your thing. 
            for every line entity created (ssadd (entlast) asdf))
);end of while

thanks pBe

all works fine with your help