x的形式为 T120X80X5，如何理解如下代码，关键是起始点和终点没搞明白

XLYS007

ntotal = Len(x)
NO1 = Left(x, 1)
If NO1 = "t" Or NO1 = "T" Then   
startpoint = 2
k = 0
Dim word(3)
For i = 1 To ntotal
NO_TEMP = Mid(x, i, 1)
If NO_TEMP = "X" Or NO_TEMP = "x" Then
k = k + 1
endpoint = i - 1
strlen = endpoint - startpoint + 1
word(k) = Mid(x, startpoint, strlen)
'MsgBox word(k)
startpoint = i + 1
End If
Next
strlen = ntotal - startpoing
word(3) = Mid(x, startpoint, strlen)