Here's the picture i tried to attach:

In CorelDraw, what I usually do in such instances is draw the straight line as a true vertical, then rotate it to as close an ideal position as possible, taking note of the angle of rotation. I then Undo the rotation, select the two ellipses, rotate them to the noted angle, rotate my line 90° to true horizontal, then Align Top for all three objects. The points of intersection are then true tangents. I perform any curve editing necessary, then rotate the group or new object the same number of degrees in the opposite direction.

My smug answer is: use FreeHand, which has tangent points. But if that's not an option, would the "Common Tangents" script work?

http://park12.wakwak.com/~shp/lc/et/en_aics_script.html

Fontforge has tangent points also... Though that might not be what you're looking for.