Si con Replace(TuTexto,vbCrLf,"<br>") no funciona (que debería de) pues quita el
vbCrLf por Chr(13) & Chr(10)
Saludos
Cita: Other constants:
vbCr Chr(13) Carriage return.
VbCrLf Chr(13) & Chr(10) Carriage return-linefeed combination.
vbFormFeed Chr(12) Form feed; not useful in Microsoft Windows.
vbLf Chr(10) Line feed.
vbNewLine Chr(13) & Chr(10) or Chr(10) Platform-specific newline
character; whatever is appropriate for the platform.
vbNullChar Chr(0) Character having the value 0.
vbNullString String having value 0 Not the same as a zero-length
string (""); used for calling external procedures.
vbTab Chr(9) Horizontal tab.
vbVerticalTab Chr(11)