Patch Offset

You could create a custom fixture profile where the DMX output is offset by that 90 degrees, or whatever is appropriate in your situation. The other way is that you can bulk edit your presets/palettes for channel 2 pan +90 to add 90 degrees to your preset. You can grab all of your presets such as preset 1 thru 50 channel 1 pan + 90 and it will adjust them all by that amount. Of course you can run into an issue where you exceed the physical limits of the fixture and you don't really want +90 but rather minus 180 or something. 

Beyond those, there are two, what are probably better solutions:
1) Go through the trouble of properly hanging the fixture.
2) Use Augmented 3d and store your focus positions as XYZ instead of pan/tilt -- this is probably the best option, because now you can just adjust the fixture in patch with it's actual orientation and the console will do the math to correct the actual pan/tilt value. 

You could create a custom fixture profile where the DMX output is offset by that 90 degrees, or whatever is appropriate in your situation. The other way is that you can bulk edit your presets/palettes for channel 2 pan +90 to add 90 degrees to your preset. You can grab all of your presets such as preset 1 thru 50 channel 1 pan + 90 and it will adjust them all by that amount. Of course you can run into an issue where you exceed the physical limits of the fixture and you don't really want +90 but rather minus 180 or something. 

Beyond those, there are two, what are probably better solutions:
1) Go through the trouble of properly hanging the fixture.
2) Use Augmented 3d and store your focus positions as XYZ instead of pan/tilt -- this is probably the best option, because now you can just adjust the fixture in patch with it's actual orientation and the console will do the math to correct the actual pan/tilt value.