Before you attack someone and say that they're being preposterous, perhaps you should read the rest of the conversation that happened (really, it was only 2 additional posts that happened pretty quickly).
I already addressed this, but I'll say it again. Personally I believe that if a married couple who stands to inherit a title or throne conceive or carry a child through artificial means (using invitro or surrogacy or what not), so long as the parent through whom the line descends is contributing genetic material, the child should be able to inherit. However, as has been pointed out, it's all rather murky and various laws of succession do not take into consideration artificial means of conception. It's kind of a bit more complicated then "you two are married and your child has genetic material from both of you, so it doesn't matter whose vagina he/she popped out of."
It's very likely that if a married royal wanted to have a child via a surrogate - especially someone in the direct line - then the laws of succession would have to be altered in order to make it clear that such a child - so long as they have the royal genes - is eligible to be in the succession, and as the current attempt to change the succession act for the BRF has shown that's not exactly a quick process.