highlight cells that contain the same first 5 characters

Hi everyone,

I was hoping someone could help me. I need to find out if there is a formula I can use in conditional formatting. If I have data such as:

ZR234-123456
TS123-456789
ZR234-645678

I need to figure out a way to highlight the cells that have the same first 5 letters/numbers. Not sure if that's possible?

Thank you!!!