My thinking is that you would use either Conjuring or Summononing to do something like what you're suggesting. With Conjuring, you're basically crafting a body that looks like you out of ectoplasm, then giving it rudimentary animation. Either you'd control it completely (in which case you'd have to give it full concentration, but it would be as believeable as you're capable of making it), or you'd control it via sent commands (it would follow one command until you sent it another, freeing you to do other things, but leaving it less able to respond to unforeseen circumstances), or it would operate under a preprogrammed set of commands (autonomous, but uncreative). This would be the equivalent of Greater Glamours, though likely with less finesse.
The other option would be to summon ... Something and creating a body for it (as above) that looks like you. This would allow the 'copy' to think for Itself ... which could be good or BAD. I'll let you decide where the emphasis should be on that last sentence.
In either case, the copy would likely be entirely unable to cross thresholds, could impersonate someone no better than you (or the Something) could, could certainly manipulate objects, could NOT cast spells (unless the Something could), with independence described as above.
That's my take on the subject, at least.