Oops! I missed the leading comma after the first string. Sorry about that!
The sample should read:

Dim sTemp As String
sTemp = "" 'initialize
sTemp = sTemp & "my,values,here"
sTemp = sTemp & ",continue,myvalues,fromhere"
sTemp = sTemp ...and so on

This makes it easier to update and ensures the final string doesn't end with
a comma.

Garry