Ssget with option "C" and -4 code filters. Unable to select.

Can somebody elaborate a bit about this -4 code and filters with wildcards in a selection set and explain how it really works? I am using the following:

(setq pt '(0 0 2.5))
(setq ss (ssget "C" pt pt (list (cons 0 "LINE") (cons -4 "=,=,*") (cons 10 pt))))

My intent is to pick a line that passes through point 'pt' and make a selection set with this one only regardless how many other are crossing behind this line (visually passing through the pt).

If I use the following it gives me always nil eventhough my line passes through this point (pt).

(setq ss (ssget "C" pt pt (list (cons 0 "LINE") (cons -4 "=,=,=") (cons 10 pt))))

Why is that?

DXF group 10 is the line start point, therefore, your ssget filter list is currently only permitting lines whose start point is at (0,0) and which pass through the point (0,0,2.5).

Thanks. It is a bit clearer now. At the end, would it be possible to select just this line somehow by clicking an arbitrary point (not start or end) withough selecting other lines behind but visually passing through pt?

I finaly managed to do it this way (at least I think)

(setq ept (osnap ppt "_endp"))
(if (not (setq st (ssget "C" ppt ppt (list (cons 0 "LINE") (cons -4 "=,*,*") (cons 10 (list (car ept) 0.0 0.0))))))

(setq st (ssget "C" ppt ppt (list (cons 0 "LINE") (cons -4 "=,*,*") (cons 11 (list (car ept) 0.0 0.0)))))
)

where ppt is any point belongin to the line.

If you have ppt - any point belonging to a line and you want to select that line, wouldn't this be enough :

(setq ss (ssget "_C" ppt ppt '((0 . "LINE"))))
(setq s (ssadd))
(repeat (setq i (sslength ss))
 (setq line (ssname ss (setq i (1- i))))
 (if (vlax-curve-getparamatpoint line ppt)
   (ssadd line s)
 )
)
(sssetfirst nil s)

True, and it seems your way works for any entity.

EDIT: Actually it does not. Anyone knows an other command instead of vlax-curve-getparamatpoint, that can pick blocks?