Broken expansion tank bracket/thermostat housing

Anyone know a part number for this? I made a couple threads already, but was referring to this thing as the lower radiator hose. Definitely not what it is. Its the part that the transmission tstat is sitting inside once u take the expansion tank off. Anyone know if this is difficult to replace too? My tstat broke while taking et out.... and when i tried taking the broken tstat out i also chipped part of the housing it sits in. Need this part asap! Thanks