Actually, probably best handled as a Custom Tool. Using your favorite scripting tool, write a script that would take two arguments (e.g., I wrote a wee Windows .bat script consisting only of "copy %1 %2"), then create the custom tool. XML from my "SaveRevisionAs" tool:
<CustomToolDefList varName="customtooldeflist">
<CustomToolDef>
<Definition>
<Name>SaveRevisionAs</Name>
<Command>C:\P4\custom_tools\SaveRevisionAs\SRA.bat</Command>
<Arguments>%F $D</Arguments>
<InitDir>C:\P4\custom_tools\SaveRevisionAs</InitDir>
</Definition>
<Prompt>
<PromptText>Save Revision As ...</PromptText>
</Prompt>
<AddToContext>true</AddToContext>
</CustomToolDef>
</CustomToolDefList>