Do you mean a stand to hold music as you play, not the instrument itself? I don't have plans or know where there are any, but it should be pretty simple. Most regular music stands would work. Some have deeper shelves than others and are, therefore, better suited for holding a binder or book of music than others. A lot of people use a stand like Lee Felt (The Dulcimer Bag Lady) sells at this link.
Others sell or make smiilar stands, so you might check various vendors of dulcimer items. I hope that helps.
One other thing, you might consider posting questions like this in the "Mountain Dulcimer Beginners' Area" section of this board. A lot more people visit that area than the Marketplace so you would have better luck getting answers.
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