Create a line on a plane

So, this may have a very simple solution, but somehow i havn't managed to do this...

I want to create a simple straight line, that can take a plane as an input (finally there should be a line geometry which i want to "drop" on multiple planes).

for example - a circle component has a plane input. a line doesn't, it has points.

I know 2 points dont define a line, but still, i would like to somehow create a code for a line which i can drop eventually on multiple planes.

thank you,

Daniel.