FX_PlayEffectBetweenPoints(<sEffectName>, <sVolumeName1>, <sVolumeName2>, <fScale>)
Spawns the given effect at a point between the two given points. Scales the effect by <fScale>. Returns the <iIndex> of the effect which can be used to stop it.
Returns an index number.
FX_PlayEffectBetweenPoints("pro_tech_beam_combo", "EffectPoint03", "EffectPoint01", 10)
<sEffectName>: the name of the effect; must match a file name in data:art/fx/ directory
<sVolumeName1> and <sVolumeName2>: the name of the volumes between which the effect is to appear.
<fScale>: a float number that sets the scale of the effect. Larger values increase the size of the effect.