Origin of imported SVG files

When I try to import a SVG file created with inkscape, the vertices relative positions are OK, but the origin isn’t, and I can’t figure out what it is exactly. It also seems to vary depending on the unit I set for the inkscape file.
I need the vertices positions to have the exact same values (numerically) as they have in the SVG file. A method to translate all vertices by a given value would do the trick ( like dragging with the mouse, but by an exact value ).
Thanks for any help.