The KPI component is actually just a specific HTML/CSS combination, so one option is to use an HTML report component to mimic a KPI:

The above KPI for instance was created via: (top) Ribbon > Insert > HTML.
Here's the HTML I used:
<ul class="kpi-bar-horizontal" style="-moz-border-radius: 6px;-webkit-border-radius: 6px;-khtml-border-radius: 6px;border-radius: 6px;background-color:white;border: 1px solid gray;padding:0px;margin:0px;width:99%">
<li style="padding-left:5px;padding-right:5px;">
<span class="kpi-bar-text1">
Internal Headcount
</span>
<div class="kpi-bar-value">
<span style="color:black">
<%=NumberFormat(Labor Master Data.Labor Headcount,"###,###")%>
<%=If(Labor Actual to Plan < 0, "<span class=""kpi-bar-pct-positive"">"&Abs(Labor Actual to Plan)&" Under", "<span class=""kpi-bar-pct-negative"">"&Labor Actual to Plan&" Over")%>
</span>
</div>
<span style="font-size: 90%">
<font color="#808080">
Planned Internal Headcount: <%=NumberFormat(Planned Headcount,"###,###")%>
</font>
</span>
</li>
</ul>
I also added a new metric (within the Metrics tab):
Labor Actual to Plan = Labor Master Data.Labor Headcount - Planned Headcount
...which the HTML code uses.