We are trying to hardwire a new range. The already existing hardwire from the wall has a has three cables a red
, black and a bare cable. The 220v oven has 4 cables
A red, black, white and a ground. How do we connect this?

If the grounded conductor of the existing feeder cable you have is at least #10 copper or # 8 aluminum of an SE type cable, then in accordance with NEC 250.140 exception the neutral and ground wires of the oven may be connected together to ground pin of the of the cord set or the bare wire of the existing feeder cable. Of course the Red and Black cables are the HOT conductors...
If you are not sure about this write back until you are...

The first place you need to look at is the electrical instructions that came with the new appliance.

If they do not allow for a three wire connection, then eirher return the appliance or install the proper 4 conductor circuit from the panelboard to the appliance outlet.

If the grounded conductor of the existing feeder cable you have is at least #10 copper or # 8 aluminum of an SE type cable, then in accordance with NEC 250.140 exception the neutral and ground wires of the oven may be connected together to ground pin of the of the cord set or the bare wire of the existing feeder cable. Of course the Red and Black cables are the HOT conductors...
If you are not sure about this write back until you are...

Dangerous and Incorrect, wrong interpretation of the code section and terminology.

The exception is for using the grounded conductor (NEUTRAL) for grounding the appliance.
It definitely doesn't apply to using the grounding conductor (GROUND) to be used as a substitute for a missing/ not present neutral.

Grounding and grounded conductors are NOT THE SAME THING

Op needs a neutral, which is not present, the appliance has 120v control/lighting circuits that require a neutral.
Either get another appliance that does not need a separate neutral, or replace the cable from the panel with a four conductor cable.

Shuntripper...
Please carefully review NEC article 250.140 exception, if you have the Handbook the explanation or intent of this section is explained in good detail.
If this was a "new" branch circuit, then yes it is required to be a (4) wire circuit, with two hots a neutral and a ground.
But where the branch circuit is an existing (3) wire circuit, typically an SEU type cable (which if you read the post I believe it is) connecting the neutral and equipment ground of the appliance is clearly permitted. (see Exhibit 250.55 in the Handbook)
Please carefully review this section and if you wish to argue further, try again...

Just curious, HF, do you agree that the electrical specs for the appliance lead the requirements of the NEC?

I want to make sure I gave the proper instructions and I do not have either my 2008 code book or handbook with me today.

Don,
Yes, NEC 110.3(B) does require equipment to be installed in accordance with the listing and labeling provided by the manufacturer. I understand these instructions are usually generated based on the UL or CE testing procedures when the equipment was tested and approved...
I install a new electric dryer last year and the instructions detailed exactly the discussion of this post. The instructions tell the installer how to adjust the wiring if the existing circuit is only a three wire circuit...