How to set file associations for portable program?

Assume I run a program from USB flash drive or network drive.
It is not installed on the local Win 7 computer but it works.

Hence when I go to menu

START--->Control Panel--->Programs--->Default programs

this program is NOT listed there as a possible application.

So it cannot be defined as a default program for selected file associations.

How can I associate some file extensions to such a program anyway?
I guess I have to declare this program as a valid target for file associations. How does that
work (without full (re)installation)?

It may not work since the portable App is on removable media and the drive letter may change often. But you can try going to Default Programs | File associations while the USB drive is plugged in and select the file association for the portable App. It may or may not stick. It's primarily a registry value I suppose.

Hi All,
Greets,
@pstein : Sir,

1.Sir F22 Simpilot hints about:

Default Programs - Associate a File Type or Protocol - Windows 7 Help Forums
( Option Two > steps 1,2,3 > 5,... )

To find & recognize the app executable(s), you may need to ''show extension for known file types''

File Extensions - Hide or Show - Windows 7 Help Forums
(Option One)

2."Hence when I go to menu

START--->Control Panel--->Programs--->Default programs

this program is NOT listed there as a possible application.

So it cannot be defined as a default program for selected file associations."

Portable programs are not listed there for sure.

( But all the installed programs are not even listed there.
For eg. 7zip . It gives extensions addition option in ''App > Tools > Options > System''.While WinRAR is directly listed there.
Another eg. is MS Office 2007/2010! It allocates almost all the extensions automatically but not all ! And it lists only two programs there i.e. Outlook & Onenote )

3.There are mainly two types of portable apps (a) standalone & (b) zip/installer extracted folder. Standalone portable app maintains all the settings,etc. in the single executable while Zip/Installer extracted portable apps maintains it all in the different components of the folder but within the folder and doesn't touch other system parts significantly. So, Portable apps are portable and you can take/maintain them on USB drives and/or internal disk by just copying the executable & folder. Standalone executable doesn't need to do anything but for Folder Extracted portable apps, you have to recognize the app executable, create its shortcut and send it to the desktop to excess it from there ! The things become a little tricky to recognize the main app executable(s) when the folder contains more than one executable . For eg. KINGSOFT OFFICE SUITE portable ! It has different executables for different types of files/extensions.

Thanks & Regards. ...