At least here in Madrid (and in all major Spanish cities, I'm sure), there are both the general hardware stores (called "Ferreterías") as well as plumbing and bathroom/kitchen fixtures/accessories stores called "Fontanerías". The latter would be my best bet to find something like that. As for what they're called in Spanish, I have no idea - but will try to find out and let you know later.
for Barcelona information, Transportation, Lodging, & much MUCH more!
Curious about what could POSSIBLY be inside the brain of MadridMan? Visit MadridMan's Madrid Blog