Sub test()
    Dim hLink As Hyperlink
    Dim wSheet As Worksheet
    Dim path As String

    For Each wSheet In Worksheets
       For Each hLink In wSheet.Hyperlinks
            path = Right(hLink, Len(hLink) - 11)
            hLink.Address = "\mysrv003" & path
        Next hLink
    Next
End Sub

path = Left(hLink, 11) ' throws error: Object doesn't support this property...

path = Mid(hLink.Address, 12) ' returns "somepathdocuments.doc"
' or, equivalently:
'path = Right(hLink.Address, Len(hLink.Address) - 11)

Sub test()
    Dim hLink As Hyperlink
    Dim wSheet As Worksheet

    For Each wSheet In Worksheets
       For Each hLink In wSheet.Hyperlinks
            hLink.Address = Replace(hLink.Address, "\mysrv001", "\mysrv002")
        Next hLink
    Next
End Sub