How do I change part of my text via xml when submitting a form to email, to bold text?

Hi,

I have the following in xml souce (with additional),  which pre-populates the email from a regular button set to submit,I have this so that the layout of the email is great..  but I need to make the words Line Manager-  for example  bold text

I have tried adding <b> before and </b> after with no success.

<submit format="pdf" textEncoding="UTF-16" xdpContent="pdf datasets xfdf" target="mailto:email@health.qld.gov.au?subject=Completed Travel Form for Approval - Traveller - Date&amp;body=Dear Line Manager and Approving Officer (Add names).&#xA;Attached is a completed QTravel Booking and Approval form for (Traveller name) to travel.&#xA;&#xA;Line Manager-&#xA;

can anyone help me please??