ModTrim

Option Explicit
Public Function Trimmer(tmpString As String)
Dim tmp1 As String
Dim trimit As Boolean
Do
tmp1 = Mid$(tmpString, 1, 1)
If tmp1 = " " Or tmp1 = vbTab Then
trimit = True
tmpString = Mid$(tmpString, 2)
Else
trimit = False
End If
Loop Until trimit = False
Do
tmp1 = Right$(tmpString, 1)
If tmp1 = " " Or tmp1 = vbTab Then
trimit = True
tmpString = Mid$(tmpString, 1, (Len(tmpString) - 1))
Else
trimit = False
End If
Loop Until trimit = False
Trimmer = tmpString
End Function

Public Function MidTrim(sString As String, Start As Long, Optional Length) As String
If IsMissing(Length) = False Then
MidTrim = Trimmer(Mid$(sString, Start, Length))
Else
MidTrim = Trimmer(Mid$(sString, Start))
End If
End Function

La funzione richiede una stringa da processare
La funzione MidTrim() richiede in input un Mid$()