html string to PDF

I want to place 15 texts in a pdf for given x,y coordinates.That mean 2 texts can be overlapped to each other..I am using iTextSharp Library.Please help me how to do this.
I saw iTextSharp is giving to place a text on PDF. My issue is how we can give the exact location. I have the x,y coordinations. But how we can do this with iTextSharp?
Is it possible to add an image as a background image? So text will be on the image background.

another way if we can use a html string as it is to convert to PDF , that will be also a solution.

tnx.

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