I don't know about growing it in the house, but I do know this plant DOES NOT tolerate drying out. I grow it as a pond plant, so you may try keeping it is a shallow saucer of water. Also, give it as much light as you can.

I think Josh is right on about Isolepis cernua 'Fiber Optic Grass'.

Santa Rosa Gardens says this "This sedge might do the trick in a perpetually wet or boggy area".

Magnolia Nursery says "This is a plant that will do great near water or in moist soils".

You can trim these grasses back, but I wouldn't cut them back too hard.

Growing indoors is tricky since you need to keep moist , yet provide the light it requires. In zone 4, you aren't going to have much of a choice but to grow it as a houseplant in the winter. Make sure you don't have it sitting somewhere near a heat register or similar now that cold weather is upon you. That will dry it out very quickly and brown the foliage.

I might add that I have no trouble keeping it going in the greenhouse during the winter. It can dip down to 45* on a real cold night and it doesn't seem to bother it. Given high light and constant moisture, I've never needed to trim it back.

Fiber Optic Plant - this one looks very interesting: Hardy to 10 degrees, loves moisture, needs light - possibility for a bare spot on an east-facing bank along a drainage ditch?

The best luck I had with Fiber Optic Grass...and this was while I was working (for 3 years) at a nursery...was to keep saucers under them, add them to container water gardens, and not TOUCH them besides selling them to water gardeners.

I also tried it in a container at home and it died very quickly since I did not follow my own advice.

They don't like haircuts at all it seems...much like juncus.

Lots of light and water and no mussing with its "DO".

:)
Mark