[HDR-photo] jpeg exposure adjustment

[Otto Feiler]

Is there a photo editor that will allow an adjustment in exposure for 
jpeg's? For example; in Raw Shooter Essentials I can adjust the exposure by 
+1, +2, -1, -2, etc. and save the changes to use in Photomatix for HDR 
conversion. I don't always shoot in RAW, or shoot a bracket series, and 
would like to be able to "create" those exposure differences from a single 
jpeg.

PS. I have PSE2, PSE3 and PSE4 besides RSE. I don't want to have to buy 
another editor if I don't have to.

I hope I've made sense of what I'm looking for in my question.

Thanks,
Otto...