Yes. Helping Hand boosts the power of your allies move no matter what it is, so long as it is an attack.
Causes one adjacent ally to have the power of its attack this turn boosted to 1.5x (this effect is stackable). Fails if there is no adjacent ally, but does not fail if the ally is using a two-turn move. Fails if used in a singles battle. This move ignores Protect and Detect. Ignores a target's Substitute. This move has a priority of +5.