First, why do you want to put text over a web browser control? Maybe there is a workaround.
Instead of a Label you can use a TextBox. With the editing disabled, the TextBox looks alike a Labe (even if it does not act alikel.
I do not know that WB control, my first idea is to grab a Paint event and write the labels myself using API. But I am a hardcore programmer Maybe some one else has a better solution.