C/C++ :: Using A Point Inside Vector?

I am trying to write a basic editor program and one of the parts asks me to "process dot commands that move point in whole line increments"

Earlier it says that a point is interpreted as specifying the location between characters rather than the characters themselves. and i need to use this to implements the following:

< moves point to the beginning of the document. > moves point to the end of the document. p moves point to the beginning of the previous line. n moves point to the beginning of the next line. k deletes the current line and leaves point at the beginning of the following line.

(there was a previous part before this so i already have some code that works) and in this part I'm trying to do a switch case

ie

for
< , >, p , n and k

I guess my question is how do i make this "point" need. Ive been using vectors, so the point needs to be somewhere inside the vector. I don't think ill be able to do what i need to do with out the point.