Yes trendyhats this can be done. There may be a different way for somebody else, but this is how I have done it and it worked perfectly for me with NO problems..open up
/modules/gateway/Print_Order_Form/orderForm.tpl and near line 18 or directly after
CODE
<td colspan="2" align="left" valign="top" class="copyText"><span style="font-weight: bold;">{VAL_STORE_NAME}</span> <br />
enter the source code you require