yep, it's possible. But I'm not sure where you're getting stuck exactly.
Regression can be found under ToolsData Analysis. If you don't see it, you'll need to go to ToolsAdd-ins first and select Analysis ToolPak
Before you select regression, you'll want your input data to be continuous. (For 3 input variables you want them to be next to each other - in columns A,B,C for example).
When you run the regression, you should get the results you're looking for (coeficients, Adj R-squared, p-values).
HTH
