Yes, you can do it in Inkscape. But
please do keep in mind if you simple copy the path data from a 'random' object in an Inkscape file, that there might be
transforms on parent groups and/or layers (svg groups with a special attribute in Inkscape's namespace), which will
affect the real absolute position as well [1].
How to convert relative to absolute coordinates:
- Change the preferences for 'SVG Output > Path Data' to always use absolute coordinates (i.e. do not allow relative coordinates). This will only affect newly created paths, or existing objects for which a rewrite of the path data is triggered.
- For existing paths, use 'Edit > Select All in All Layers', and nudge the selection with the arrow keys (e.g. one step up and one back down again). This will trigger a rewrite of the path data in 'd' which will follow the changed preferences for optimized path data.
[1] To flatten transforms (on objects as well as parent svg containers like groups): see e.g. Subject: Re: Simplify inkscape transforms. For transforms added to top-level layers after changing the dimensions of the page, add a new layer and move the objects onto the new layer (see menu 'Layer').