waste pipe & vent resiting

[hcoulson66]

House built in 2001, wanting to remodel bathroom into wet room. Before removing any tiles/plasterboard it appeared that the waste pipe run vertically down the left corner of the bathroom, concealed in a box, with a decorative pier of roughly the same size on the right next to it, with a shelf at about waist height. The toilet is currently located about 1/3 along the outside wall and we want to move it to the left hand inside wall (located next to the sink). Upon removal of tiles/plasterboard the waste stack is partially located in the corner of the room (the vertical vent only section), and then branches over to the lower part of the waste pipe which is situated below floor board level directly under the toilet, about 2 foot away by a couple of curved but not angled pipes. (I hope this makes sense). We wanted to do away with the space wasting second boxed in pier and need advice on how to connect the top half of the waste pipe to the bottom half when the toilet is moved to the left inside wall. To make things easier, bathroom walls A,B,C & D,(clockwise direction). Toilet currently located on wall A (which is the only outside wall) with lower half of waste pipe located directly under toilet about 2-3 foot from corner of wall D. Vent section of waste located in the corner of walls A & D. Back to wall toilet needs to be relocated to wall D and we need advice on what joints can be used to do this, that would unable us to do away with the second boxed in feature (on wall A immediately next to horizontal waste)and conceal the waste pipe along wall A, (wall D from the toilet to the corner will be concealed by a fitted cabinet). Help!!