>>>
>>>Here is the problem: for most operations we need to use user's configuration. Only for this particular application I need to change temp dir to something else.
>>>
>>>
>>
>>Then use the current configuration file as the basis for the new one...filetostr(), add necessary lines, and strtofile() to another config file.
>>
>>You can specify what file to use when you start the .exe.
>
>Right, except we're not running exes here. We're running .app from the main application. E.g. my application is called DataDict.app and it's called from the main JobControl's application menu... Of course, we may consider to change it to exe and change menu call... I need to discuss it with everyone be4 doing it...

You can run a new instance of VFP running that .app, with a custom tailored .fpw and any message file left in its private tmpfiles directory, so any communication between the JobControl and the .app is feasible. Even the return control can be done if you use file based messaging and use Api_AppRun to just wait until it gets done.