With some help from the late brother, I finally understood why it was not a simple 26-digit program.

The questions are as follows:

Anyone who has used excel knows that the column number of excel is as follows:
A B c... zAaAB ac... az ba bb bc... yz za zb zc... zzAaaAab aac ....
The numbers are as follows:
1 2 3 ...... 26 27 28 29 ...... 52 53 54 55 ...... 676 677 678 679 ...... 702 703 704 ....

Please write a function to complete the conversion from a positive integer to this string. Public Function intcstr () Function intcstr (ByVal ints As Integer) As String
Dim strs As String
Strs = Nothing
Do While (ints Mod 26) <> 0 Or ints/26 <> 0
If ints Mod 26 = 0 Then
Ints = ints/26-1
Strs = Chr (96 + 26) & strs
Else
Strs = Chr (96 + (ints Mod 26) & strs
Ints = Int (ints/26)
End If
Loop
Return strs
End Function