yes it is possible...
u just need to edit fonts.xml with notepad and instead of sans serif put the name of ur font..

Upload font to tpa/preset/system/fonts/

For instance:

- <xml>
- <engine cache_size="131072" default="yes">
<font style="Comic Sans MS" weight="normal">/tpa/preset/system/fonts/comic.ttf</font>
</engine>
- <engine cache_size="262144" default="no">
<font style="Comic Sans MS" weight="bold">/tpa/preset/system/fonts/comicbd.ttf</font>
<font style="Comic Sans MS" weight="italic" s01="20">/tpa/preset/system/fonts/comic.ttf</font>
<font style="Comic Sans MS" weight="bold-italic" s01="20">/tpa/preset/system/fonts/comicbd.ttf</font>
</engine>
</xml>

Good Luck

Lav