2 externnal drives, TIH 2009, weekly rotation. Possible?

Running TIH 2009 on a Vista x64 Home Premium Machine.

Here's the setup:

-I want to run nightly incremental backups of the directory c:\foo to the external HD g:\

-I have two identical external drives

-If once a week, I take one external drive off-site, and put the other one in its place (also mounted as g:\), will Acronis pick up from the last incremental backup on -that- drive?

If not, what do you recommend I use for this?