i hope this time it will work
the problem is I dont get the whole picture.
are you trying to replase #Reference# with
multiple value from list box?

Hello #Replase# ok
has to look like
Hello one,two,three ok

if the values in list box are
one
two
three

staffCount = lstSelected.ListCount
'****************************************
'****************************************
Dim sValues As String

For idIndex = 0 To staffCount - 1
sValues = sValues & "," & lstSelected.List(idIndex)
Next

sValues = Left(sValues, Len(sValues) - 1)

rtbCoverLetter = Replace(rtbCoverLetter.Text, "#Reference#", _
sValues, 1, 1, vbTextCompare)
'****************************************************************
'****************************************************************
let me know if this what you need
what kind of obezyanka are you
monky or shinpadzi?