Since you can almost always substitute yogurt for sour cream, I imagine the opposite would also be true. But I agree with AndyM. that knowing the recipe - or just the gist of it - would make it easier to give you a definite answer.
Hmmm. . . . baking is the one area where substitutions can be tricky. And since baking isn't my forte, I'll have to bow out & hope someone who's more of a baker can answer your question.
While I can't be sure, I'd say a substitution would work. The reverse sub, yogurt in place of sour cream, is often done to reduce the fat and calories in recipes such as banana bread.