Wrote a reply off-line and have been lapped several times (as usual). What Peterdjones says in his responses makes a lot of sense to me. I took a slightly different tack, which is maybe moot given your admission to being a solipsist:

I should disclose that I don't find ultimately any kind of objectivism coherent, including "objective reality".

-though the apparent tension in being a solipsist who argues gets to the root of the issue.

For what it may be worth:

I'm assuming you subscribe to what you consider to be a rigorously scientific world-view, and you consider such a world-view makes no place for objective values - you can't fit them in, hence no way to understand them.

From a rigorously scientific point of view, a human being is just a very complex, homeostatic electro-chemical system. It rattles about the surface of the earth governed by the laws of nature just like any other physical system. A thing considered thus (ie from a scientific pt of view) is not 'trying' to do anything, has no beliefs, no preferences (just varying dispositions), no purposes, is neither rational nor irrational, and has no values. Natural science does not see right or wrong, punkt.

Some people think this is all there is, and that there is nothing useful to say about our conception of ourselves as beings with values (eg, Paul Churchland). I disagree. A person cannot make sense of her/himself with just this scientific understanding, important though it is, because s/he has to make decisions -has to figure out whether to vote left or right, be vegetarian or carnivore, to spend time writing blog responses or mow the lawn, etc.. Values can't be made sense of from a scientific point of view, but we recognize and need them, so we have to make sense of them otherwise.

Thought of from this point of view, all values are in some sense objective -ie, independent of you. There has to be a gap between value and actual behaviour, for the value to be made sense of as such (if everything you do is right, there is no right).

Presently you are disagreeing with me about values. To me this says you think there's a right and wrong of the matter, which applies to us both. This is an example of an objective value. It would take some work to spell out a parallel moral example, if this is what you have in mind, but given the right context I submit you would argue with someone about some moral principle (hope so, anyway).

Prima facie, values are objective. Maybe on closer inspection it can be shown in some sense they aren't, but I submit the idea is not incoherent. And showing otherwise would take doing some philosophy.