concatenating dates

I'm trying to concatenate a client code column (in a text format) with a long form date column (2018.04.27) so the concatenated column would appear like this — BHI2018.04.27. But, when the date appears in the concatenated column it shows up as BHI09/08/20. Is there a way to make the slashes go away, or have it appear in the same format as the long form date column?