Looking for a dc to dc converter that will accept variations of voltage of a solar panel?

I would like to use my small solar panel to trickle charge me laptop computer. The computer needs an input of 19V. The solar panel's is nominally 12V but can have an open circuit voltage of up to 17V or 18V. I was wondering if there is a commercially-available DC to DC converter that will accept a sufficiently wide input range (ie 12V -17V) and converter to a regulated 19V. The DC to DC converters for cars (ie that convert from car battery 12V to laptop 19V) don't seem to accept any input greater than about 14V and my solar panel will therefore cause problems at full output. Any ideas?