In my Lenovo W500 I have spare miniPCIex slot, which is normally used to the extra Wifi module or TurboCache memory module, however it's not a regular miniPCIex where you can plug mSATA,, it has a different pinout, where it also has USB2.0 lines.
So I get a miniPCIex card with 2 uSD slots which has a onboard ALCOR bridge chip.I had to patch the BIOS for whitelisting..Normally when it get's detected, installed, it's a regular removable USB,to make a fixed drive out of it I have used a Hitachi driver.
Now it behaves like a disk ,altough you can remove it via systray like example my USB3.0/mSATA disks,that I use.Probably that you can still remove it, XP refuse to create a pagefile there.