First of all welcome to the group.
I have had laser treatment on my upper gum of my PWS (Port Wine Stain) birthmark with a C02 laser I think. So far it has not been very effective. I think that would be the same laser that the doctor probably would use on the tounge. If so I would not recommend it. I would recommend getting another opinion.
There are a couple things you can do. First, under resource section at the top of this page, do a physican search for a doctor in your area that might specials in birthmarks.
Second, on the front of this website there is a section on the left hand side. I suggest writing a message to the Ask the surgeon Dr. Levintin. This doctor works with Dr. Waner. Both are plastic surgeons, but Dr. Waner is orignally an ENT doctor. If surgery is possible this two doctors would be able to tell you. I have had plastic surgery from them and highly recommend them. They are in the top of either field. Contact info for Dr. Waner is in the same section in the resource page in New York City.
If you need any other info just ask we are all here for you.