VB 如何使用下面的Function

Private Function BigEnterTXT(Num1, Num2, Num3) As Boolean
Open AppPath & "\费用表txt" For Input As #1 '打开文件
Line Input #1, Num1
Line Input #1, Num2
Line Input #1, Num3
Close #1
End Function

用法：
Dim x, y, z
Call BigEnterTXT(x, y, z)
Text1Text = x
Text2Text = y
Text3Text = z
Label1Caption = x
Label2Caption = y
Label3Caption = z