White mark on Polyurethane finish table

Hi, I hope someone can help me.
We have a newish Knotts Pine dressing table with a polyurethane "golden oak" satin finish that has an irregular white mark on it the size of two 50 cent pieces . The table top was covered with a cloth, but some sort of cosmetic or hair preparation of my daughter's tipped over, soaked through, and seems to have dissolved the polyurethane. She has no idea which one, so I can't work out what it contained. I don't think it is a water mark, as it seems to be a slight depression down from the finish to the wood.
What is the best way for an amateur to repair this? Sanding back the whole table top is not an option, because I will botch that for sure. My hubby attacked it with the Mr Sheen when he saw it, which of course did nothing, but I expect we would need to remove the Mr Sheen from the mark first to repair it.
Knotts Pine were no help, only said it was an imported product (I think most of their stuff is from China).
Is there a easy to use stain repair product we can buy?
Many thanks for any help.

Hi, I've had another look and it seems that something has definitely dissolved the finish/coating. I will need to reapply some product. The edges are quite irregular, so I am concerned about the appearance if I just paint on some tinted polyurethane. Should I sand first or wipe with something that will dissolve the current pollyurethane into a more regular shape?
Any tips please? Or places I can go for help?
Many thanks.

The big problem is that it's polyurethane. This will make it really hard to repair. You will either need to strip it right back or learn to live with it.

I make a polish reviver that should remove the white marks but because it appears to have been damaged (eaten into) it most likely won't work. Your only other option is to lightly sand the area around the marks and any damaged area hopefully without going right through to the stain. If you can do this, then lightly scuff the rest of the surface you might (might) get away with recoating it but reasonably doubtful you'll ever get it back to looking original that way.

Those marks are called patina and that is part of the history and story of the piece of furniture. This works well for a genuine antique as it adds to the mystique and intrigue of the piece. But for a recent piece of furniture.....:dunno:

Bugger just read the bit about Mr Sheen. Missed that before.:damn: Throw the dresser out. Hubby's ruined it. Give him a smack up the side of the head for his effort.

Mr sheen contains silicone which will effectively stop pretty much any finish from sticking to the surface. Our Polish Reviver will help get rid of it then you'll need to sand it or strip it back to bare timber and start again. Best to find a polisher/restorer to do it for you if you haven't done this before. Grab the yellow pages and let the fingers do the walking.

You could try the Polish Reviver and some Traditional Wax and it might save you a hefty repair bill. Might not do a thing either.

Better alternative: Call it patina, throw a runner or lace doily over it and forget it's there.

Cheers - Neil :)