Drawing Lines, help required please...

Hi there, I've been trying to draw a line off of the right hand side of a page but as yet no luck.

So for example, if you have an A4 page with the rulers at 0,0, I'm trying to draw a line at, let's say, 70mm from the top and horizontally starting at 213mm from the left to 216mm from the left.

When executing the script I have the line is drawn 70mm from the top but 3mm in from the left to 6mm in from the left?

I hope I've explained it clearly enough. If so please can someone point me in the right direction.

Thanks in advance,

Nick