>>>Simply get a object reference to the file and change its Name property like this

oFSO = CREATEOBJECT("Scripting.FileSystemObject")
>>>oFile = oFSO.GetFile((GETFILE("*")))
>>>? oFile.Name
>>>oFile.Name = FORCEEXT(oFile.Name, 'DBF')
>>>? oFile.Name

Naturally, in VBScript you'd get the object references using Set.
>>>
>>>Why would you need two parameters?
>>
>>I need to call this code with the old file name and the new file name. In fact, I need to create a file with a long name in Fox Pro 2.6, so my idea was to write a copy file tool that takes the two parameters.
>
>Then you'd just need to change the ShortName property of the file object reference. There's also ShortPath as well as Path.

The problem is, that FoxPro2.6 just strips off the latter part of the file name. I can only create a file like
FHndl = FCREATE("ShortFil.txt")

In order to create a file with the name "VeryLongNow.txt" I need to call a 32 bit application like:
! /N RenameFile("ShortFil.txt","VeryLongNow.txt") because there is no other way in FoxPro 2.6.