If the 5* have the same marker ipt bindings as the AC4, it is possible to change the mounting position.
I had the same problem with my wife AC4 (she liked the position in powder but could not flex the ski enough on hard pack) and wanted to be moved 10 to 15 mm forward.
To achieve this, it is necessary to remove the bindings from the rail and playing with the boot size adjustment system.
This can be easily done by extracting the pin that locks the binding in the rail below the heel piece (rotate the pin 1/4 turn counter clockwise and push it through the small hole from the other side).
You can now slide the complete binding out of the rail (you also need to unscrew the piece that attaches the piston at the front of the ski if there is one... I also recommend you remove the brakes and put them back when every thing is corrcertly adjusted)
Looking at the binding upside down, you should see that the toe piece is only attached through the plastic screw that is used for adjusting the spacing between the toe and the heel.
In fact it is a platic square piece (with a thread in the middle to provide the translation movment for adjustment) which is clipped on the toe piece.
You need to unclip the toe piece from this plastic piece.
In order to move the binding forward, you need to rotate this plastice "nut" as required.
The only issue you might have is that it is necessary to move the toe piece by around twice the amount of the forward position shift you want to achieve. If you spouse has little boots, you might not be able to achieve that much (20 mm fwd would be the most I could get for my spouse who has 295 mm sole boots).
You now have to clip the toe piece back on the plastic square piece.
At this stage it is already a good idea to readjust the toe to heel distance for your spouse boots and verify how much fwd shift you have achieved.
You can now slide the binding back on the rail, put the locking pin back in place, rotate it clockwise 1/4 turn, put back the brakes and re-attach the piston.
The dialing system is now off by the the amount you moved the toe piece and you should be careful when adjusting the binding.
In any case, have them checked by a professional.
Hope this can help other persons trying to setup Volkl ski for our dear ladies