Hi,
There is another option, if you are willing to edit the XML Source of your form.
When you insert a floating field Designer will insert a bit of xHTML in your text object that looks something like;
<span xfa:embedType="uri" xfa:embedMode="raw" xfa:embed="#floatingField016841"/>
The "floatingField016841" bit is a reference to the hidden field containing the value to insert.
You can also have xHTML that references a SOM expression, so in your case assuming your form is called form1
<span xfa:embedType="som" xfa:embedMode="raw" xfa:embed="form1.myVar"/
Will insert your global variable.
Saves the having the hidden field
Bruce