positioning a feature of an assembly properly

hello,

I assembled 2 components and now I'd like to drill through both.

The sketch that defines the possition of the drill hole is a 3D sketch which is fixed.

When I move the parts now, the sketch stays where it is.

It gets screwed up because the feature (the sketch of it) does not move along with the component.

How do I fix that?

thanks.

SolidworksAssemblies