Linq to update a collection with values from another collection?

I have IQueryable<someClass> baseList

and List<someOtherClass> someData

What I want to do is update attributes in some items in baseList.

For every item in someData, I want to find the corresponding item in baselist and update a property of the item.

someOtherClass.someCode == baseList.myCode

can I do some type of join with Linq and set baseList.someData += someOtherClass.DataIWantToConcantenate.

I could probably do this by iteration, but is there a fancy Linq way I can do this in just a couple lines of code?

Thanks for any tips, ~ck in San Diego