Whitespaces created in multi-child elements when using Excel to open XML file

I have created a little script that creates an XML file for the user. However, the XML file created will always have an exponent in one of the elements. In order to present this, I wrote:

<Cell ss:MergeAcross='1' ss:StyleID='m302852124'>
    <ss:Data  ss:Type='String' xmlns='http://www.w3.org/TR/REC-html40'>
        <B>
             <Font>ΔP (kgf/cm</Font>
             <Sup>2</Sup>
             <Font>)</Font>
        </B>
    </ss:Data>
    <NamedCell ss:Name='Print_Area'/>
</Cell>

That is accepted and runs smoothly when opened in Excel, except for the fact that the output is:
" . . . . . . . . . . . . . . . ΔP (kgf/cm . . . . . . . 2 . . . . . . . ) " [periods placed to display extra white spaces which are otherwise truncated in this forum]

This problem also repeats itself in the case of

<Cell  ss:StyleID='s32'>
    <ss:Data ss:Type='String' xmlns='http://www.w3.org/TR/REC-html40'>
        <B>
            <Font>ΔP  (kPa)</Font>
        </B>
    </ss:Data>
    <NamedCell ss:Name='Print_Area'/>
</Cell>

Where the output is:
" . . . . . . . . . . . . ΔP (kPa) . . . . . . . . . . "

Other elements, containing no child-elements under <Data> have no such spacing problems. It's also worth mentioning that I built the script by creating a template on Excel and then saving it as an .xml instead of as an .xls