Well, currently there are not as many tools at hand as there are in QCAD....but a quick way of using what there are so far is to:
1. Set up a new layer - 'Construction'.
2. working on this new layer, place a vertical construction line at the precise coordinate point you need, either by mouse or entering the co-ord points in the command line.
3. Now working on your original layer, use the divide tool (from modify tool-set) and use your construction line as the reference point!