About plotting functions in a file

[Fabio Male]

Hi everyone,
I have to plot some functions provided by a file "Example.dat"
The functions are straight lines and parabolas so:
y = mx +q [0:6]
y = m_1x+q_1 [6;10]
.... et al
y = ax^2+bx+c [-3:0]

But unfortunately gnuplot doesn't recognize anything, but it tries to plot several points dealing that as a data file. I don't want to copy and paste each function, even because there are too many functions.
Any suggestions?

Thanks in advance for help

Fabio