A Line From One Point Past Another Point, And Whether It Hits an Object

I am using AS2 with Flash 8 Professional

So, my problem is that I currently have a man in the middle of the screen, who shoots a line towards the mouse when I click. However, when I use hitTest to see if the line collides with another object, Flash recognizes the line as a large box if it is diagonal, so the hitTest isn't very accurate. The line only satys there for one frame, so I can't have the usual moving-bullet-style.

I am either looking for a way to create an imaginary line with AS from the starting point to the mouse and beyond, and tell whether or not this line intersects with an object...
or some other way that I haven't thought of to fix my problem.

Keep in mind that the line rotates from a center point towards anywhere around it for 360 degrees.

Thanks in advance!