combobox with two columns?

[behedwin]

i have this code to populate a combobox

    Dim c As Range
    
    With Sheets("REGISTER")
        For Each c In .Range("B8", .Range("B" & Rows.Count).End(xlUp))
            If c.Value <> "" Then ComboBox_members.AddItem c.Value
        Next c
    End With

but i want to populate a combobox with both data from b column and c column.

how do i do this?

in b column i have first name
in c column i have last name

in the combobox i want to show full name

and it is important that the combobox updates when another row of names is added... so i cant have fix range.