Question: Splitting an equation by its addition terms.

Hi, I wondered if anyone knows a way to separate out addition (or subtraction) terms in an equation.

For example given eqn1:

eqn1:= (1/2)*p+1+(-4*p^2-p-1)/(3*p^3+7*p^2+2*p+2)

I would like to get the first rational term before the first plus (or minus) sign. In this case it would be (p/2).

This is a trivial example shown above but the real value in this is that I want to customize my own factorizations using the pratial fraction function of Maple. In this case I would not know eqn1 before hand but it would be the solution to some previous factorization and I need just the first term (before the first plus sign).

If anyone knows any tips or tricks that will set me on the right path to doing this it is most appreciated.