How Sweet is lactose?

I made some ginger beer for friends and, since they like the taste sweeter, like commercial ginger soda, I added Ativa sweetener. (Yeah, I know, I could have just made no alcohol ginger beer that had to be refrigerated but these people are adult drinkers, not my grandson.) They like it but it still tastes chemical to me. Does Lactose actually have enough sweetening power to work in this situation?

I'm no expert, but...I made a XX cervesa recipe out of the Brewmasters Bible, and it called for 4 ounces (I think). The beer was sweet but not over the top sweet. slightly sweeter than an ESB