Concept for a Eurorack sequencer

For all I know, this already exists.  This is also the first time I've written it down, so it may not even be possible and I haven't realized why yet.  I just want to write it down before I forget it.8 or 16 steps/stages.  For each stage:1 slider/knob, one input jack, two output jacks. , one  switch, two toggles button.  With nothing plugged into the input jack, the slider/knob sets the output valueWith a CV source plugged into the input, the knob/slider will attenuate the value of that CV at the output.  The switch has three positions - UNI, BI and S/H.  in UNI, the CV will go from 0~5v.  in bi, it goes -5 to +5 and will invert the CV coming in if it's, say, and LFO when it goes negative.  When it's in SH/mode...more on that later.The next section is your standard sequencer controls - clock input, reset in/out, etc.  As the sequencer steps through, it will pass the output from the above sections to the output one at a time.  the SH of each input is triggered by the clock coming from the sequencer section, so it will sample/trigger in order.oh, and the final output jack on each stepThis seems like a cool / useful thing.oh..the toggles.   The first toggle turns the step/stage on or off.  If the stage is off, the prior stage will continue to be present at the output until the next 'on' stage.   The second toggle works in S/H mode to determin if the trigger should cause a new sample to be taken or not (could be fun...sounds fun to me).I have no idea how to build it, so I am doing so in reaktor :DOpinions?