Hi Priya,
I don't know of a way to query out the origin position, but I do have a low-tech solution that should work fine for your described scenario. I'm assuming that regardless of the floating limits on your automatically scaled X and Y axes that your origin is always at (0,0) or some other constant (X,Y) value. If this is the case, then you can create 3 new channels in the Data Portal (I created them in a separate group) which contain that (X,Y) information. Then create 2 additional curves on your 2D axis of type "Line and symbol" with a blank color. You need 2 curves because you will get 1 symbol for each curve, and you want to display text both above and below the origin. Then configure the text and its display for each curve, and now those texts will always be displayed relative to the origin, no matter what the automatic scaling does to the start and stop values of each axis.
See the attached example,
Brad Turpin
DIAdem Product Support Engineer
National Instruments