Chris, you are asking to re-write the Red Pill exploit in PS.
That is in fact not a big problem since one can easily use any .Net language with the CompileAssemblyFromSource method.
But is there really a point in doing this ?
I can only see the Red Pill being used in honeypots, not in 'regular' guests. For me there is no real value in accepting your challenge (albeit it an interesting exercise).