Indenting Text Minus Vertically

Hi,

I have a text object set to 50pt, and when it is placed within my text object there is roughly a 10mm space between this and the top of the text box.

I need the object to sit flush with the top of the text box. But when I try to put in minus figures within my paragraph style it does not let me do so, and moving the text box to compensate is not an option.

Is there anyway to set a minus indentation?

Thanks

Steve