Could a sperm be altered to contain a female's genetics?
You might be interested in this article. In this study they created haploid ES cells from artificially activating an unfertilized oocyte and growing the haploid cells. These cells, when introduced in the ICM, give rise to viable chimeras. 

In another study, haploid androgenetic ES cells were created by injecting a sperm into an enucleated oocyte. These cells also are capable of creating offspring when fused with another oocyte. [See this post also]

Also, since these cells can be cultured, they can be genetically modified. However, they undergo spontaneous diploidization and lose reproductive potential after a few rounds of division. This is related to the alteration of epigenetic status of these cells on certain imprinted loci. Others have also indicated the importance of both paternal and maternal imprinting in the viability of embryos which might be a problem in oocyte-oocyte derived hES cell fusions (See cross references). [Check this article too].

It can be concluded that oocyte$-$oocyte-hES fusions are not observed because of same imprint status (Also mentioned by Chris in the comments). AD-hES also lose their paternal imprints on prolonged culture (but retain maternal imprints). It is to be ascertained if paternal imprints are more unstable compared to maternal imprints under these conditions. It may be possible to optimize the culture conditions such that oocyte derived hES lose their maternal marks: would that lead to incorporation of paternal marks post-fusion is debatable.