[Gnuplot-info] to emebed or not that is the question?

I am building a small dll, on windows with vc6.0,but i need now some 
plotting library to display functions y=myf1(x) and surfaces
z=myf2(x,y). i was thinking of scripting gnuplot at first were my
library would create some input files then i wound from my library
start  the gnuplot executable and run the input files. is that the best
way? or should i embed some gnuplot stuff directly into my dll,that
would force my entire project to be free/opensource, but i am ok with
that a long as i get something that works for me.This dll is just a
small tool that i need to do my work better,it is extending a bigger
application. i won't mind sharing the dll tool if it becomes free too.
please let me know  any idea /pointers are welcome.
Maybe i am going totaly the wrong way, so please help.
Thanks,
Kemal