try the following

Dim Str1, Str2, Str3, Str4 As String

Str1 = "The is a test"
Str2 = "of string array concatenate example"
Str3 = "First Load the Array with strings"
Str4 = "Then load a string to pass to the rich text box"

Dim Array1()
Dim Array2()

Array1(0)...