Prevent MCE From Recording A Specific Episode In A Series?

Before moving to Windows 7 MCE, I was using a dvr program called Beyond TV made by Snapstream. It was very intuitive and easy to use and it gave a lot of control over how/what/when/ bitrate/format/etc. to record.

I've made my peace with relinquishing control over format and therefore overall recording size of programs etc. but there was a nice feature that I would like to be able to use in MCE.

I was able to prevent a specific episode i a series from being recorded like say, for example, do not record the 5th and 7th episode of Season 1 of Grimm because I already saw them and don't want to waste cpu and tuner use.

Is that possible or do I have to let MCE record it so that it can then add it to the "watched" list and stop trying to record it.

how do I "re-enable" a show that was already recorded to be "re-recorded" again. It's very rare but sometimes due to a glitch in the guide, MCE will record something, but the actual show was not recorded because the guide was erroneous and now it thinks its been recorded and skips trying to record it.