Concatenate Multiple Strings Of Text With Formatting

I am trying to concatenate multiple strings of text where each may have composite or compound formatting. Is there any way to maintain the formatting? The Characters.Insert method won't work because the resulting string is greater than 255 characters. See an example below.

String 1: When you simply concatenate
String 2: these strings, Excel discards
String 3: formatting at the character level.

Required Result: When you simply concatenate these strings, Excel discards formatting at the character level.