The Yerushalmi (Dmai 7:4, 32a in Vilna ed) has a machlokes Amoraim whether a person can seperate terumos and ma'asros on erev Shabbos on the condition that the hafrasha will be chal only on Shabbos. The conclusion of the Yerushalmi is that it would be permitted.
R' Akiva Eiger discusses in the tshuvos (159) whether a person can make a kinyan on erev Shabbos which will be chal on Shabbos. The Terumas haDeshen writes that pidyon haben is not done on Shabbos because even if the money were given to the kohen before Shabbos on condition that the pidyon be chal on Shabbos, the bracha on pidyon could not be recited. The implication of the Th"D is that if not for the bracha, the pidyon could be chal on Shabbos. This issue is also relevant when erev Pesach falls out on Shabbos --can a mechiras chameitz be done before Shabbos which will be chal on Shabbos? Contemporary poskim raise the same issue regarding internet sales and transactions which are chal on Shabbos without the seller taking any action.
Sounds to me like the question raised by RAK"E is exactly the same issue being debated in the Yerushalmi -- does the gezeirah prohibit the act in question or even the chalos.