I forget- can you add exp to cost of upgrading units?

[Emacz]

Want to try something new with Merc in Classical Warfare AEA.  I havent tried yet, cause I figuted I would ask before nubbing and creating errors.  Can I write it so the Promotion is includeded in the upgrade?  

 <Upgrade>

    <veteran>

      <Entity>units/athen/merc_inf_archer_market_a</Entity>

      <Tooltip>Rank up to veteran status.</Tooltip>

      <Cost>

        <metal>10</metal>

      </Cost>

      <Variant>upgrading</Variant>

      <Time>10</Time>

    </veteran>

  </Upgrade>

  <Promotion>

    <Entity>units/athen/merc_inf_archer_market_a</Entity>

  </Promotion>