Zoom to center

Please can someone explane me about the value , that request when we try to

zoom to center.

And why cant we activate snap on during this option.

Try these which working? red can be modified= magnification/ height

(command "zoom" "c" (getvar "viewctr") [color="red"]10[/color])
(command "zoom" "c" (getvar "viewctr") "H" [color="red"]10[/color])
(command "zoom" "c" (getvar "viewctr") "M"[color="red"]2[/color]) 

Ok.thanks a lot . I will try your codes

(defun c:zc()
(setq ss (car (entsel "\nSelect  line:")))
(setq assolist (entget  ss))
(setq end1 (cdr(assoc 10 assolist)))
(command "zoom""C"end1 2000 "")
 )

I try to zoom to one end of the selected line using above code.

It is working nicelly. but in some drawings (Test 2)the line dissapier

why that.

TEST1.dwg

TEST2.dwg

Mistake found mysels.

I have to set UCS to World

Also consider the zoomcenter method of the Application Object, e.g.:

(vla-zoomcenter (vlax-get-acad-object) (vlax-3D-point 1 2 3) 10.0)

On 10/2/2014 at 12:48 AM, Lee Mac said:

Also consider the zoomcenter method of the Application Object, e.g.:

 

(vla-zoomcenter (vlax-get-acad-object) (vlax-3D-point 1 2 3) 10.0)

 

 

Thnx Lee Mac!

I did this:
(setq ZoomCeneter (vlax-3D-point (getpoint)))

(vl-propagate 'ZoomCenter)

If you use (vl-propagate 'ZoomCenter) you can use it in all opened docs