MSBuild 4.0: Changing command line switch from slash to hyphen

Question

In VS 10 and MsBuild 4.0 the "\Program Files\MSBuild\Microsoft.Cpp\v4.0\cl.xml" file contains descriptions of a property, for instance:
    <EnumValue Name="TurnOffAllWarnings" Switch="W0 ">
      <EnumValue.DisplayName>
        <sys:String>Turn Off All Warnings</sys:String>
      </EnumValue.DisplayName>
      <EnumValue.Description>
        <sys:String>Level 0 disables all warnings.</sys:String>
      </EnumValue.Description>
    </EnumValue>

It gives / W0 option in the command line even though the slash seems not to being specified anywhere.

We're creating a similar set of files for our compiler, but it uses options with hyphens.
Is it possible to change the slash (/ ) to hyphen (- ) somehow in the XML description or MSBuild target files?

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Anton