Well, you could reinstall the application from the desktop . . .
Unless you have the CAB file, I'm not sure what you can do. If there isn't an x86 CAB but there are CABs for other processors, you could try installing it on another device with one of those processors and then look for registry keys in HKEY_LOCAL_MACHINE/Software and HKEY_CURRENT_USER/Software corresponding to the app in question and export those keys to import into the x86 device.
(I've started getting into the habit of copying registry keys for installed programs into the those programs' folders on the Storage Card, because they take up very little space and you never know when they can come in handy. I do it in Total Commander because it's simpler than using a registry editor. Registry keys generated by CAB files can be viewed in MSCEInf on the host PC, but copying them from there is a little more complicated.
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