You can convert some LV data types into .NET types via the To Object.vi, which you'll find in <vi.lib>/Platform/dotnet.llb. So, for example, you could wire an int32 or double into the To Object.vi, and wire the output of that VI (which is a System.Object) into your invoke node.
To get the value back into a LV type, use the To Variant.vi (same LLB) and then use the normal Variant to Data node to convert it to the LV data type.
