2003 Volvo XC90 passenger side view mirror

2003 Volvo XC90

I broke the unti but its still attached to the car. The mirror is completly gone. I found a dealer that can replace the mirror. It there some kind of putty or something that I can buy to patch up the cracks in the back of the unit as a temporary fi, until I can have the whole until replaced. I'm desperate to fix it before my husband see's it and freaks out