The easiest thing to so for a 5 cycle sinewave in SPICE transient analysis is to have a SIN transient source and a PWL gate to it. Use a poly controlled source to take the product of the two. Set the PWL source to zero when you want the sinewave gone and 1 when it is active.
vs 1 0 0 sin(0,1,1e6) vp 2 0 0 pwl(0 0 5u 0 5.001u 1 10u 1 10.001u 0) e1 3 4 poly(2) 1 0 2 0 0 0 0 0 1 makes the signal you want between nodes 3 and 4. h.
