how do i wrote interpreter?

I want to implement a scripting language in my project.

I don't want to use Lua, even though it's the easiest way I know how.  Instead, I want to write my own scripting language interpreter into my program.

I've a B.S. degree in Computer Science so I know most of the fundamentals, but not the advanced practicalities.  For example, I can probably write up a formal grammar for whatever scripting language I wish to use -- but ... then what?  How do I apply that knowledge, to what I wish to do?

Any good sources on this subject that isn't targeted towards Ph.Ds with Masters Degrees, but good enough for someone with a B.S. degree level of education?

>>2
I never understood how to use flex and bison.  Their documentation seems targeted toward people who already know the syntax of the files flex and bison read.

>>3
But this seems more pragmatic and user-friendly to someone like myself.  I'll try it out, thank you.