All you need to make your offspring is to combine the nucleii of two eggs. I don't know if injecting on egg nucleus into another will kickstart it into fetal growth; it might need sperm touching its outer cellular wall to start the chemical changes that commence the process. It might be a process of penetrating the host nucleus as well and combining the two, or, one could remove a nucleus from EACH donor, combine them, and inject the result into another egg that has had its nucleus cleared.
Or, if you remove the nucleus from one egg and inject it into a similarly cleared sperm, then fertilize another egg with it, that might be easiest - however the nucleus of the egg might be too large for the sperm cell; I don't recall their relative sizes.
Another possibility would be to inject one egg nucleus into another egg, then kickstart it with a sperm cell that had its nucleus removed.
I don't know if this degree of microsurgery exists, for sperm cells are a LOT smaller than eggs.
All in all, I'd be pretty surprised to find out that none of this is currently possible. It might be however, that the failure to success ratio would be so high that it simply isn't done at the present time.