You can try:
https://vborg.vbsupport.ru/showthread.php?t=233120
OR
https://vborg.vbsupport.ru/showthread.php?t=233629
For using an image perhaps a different take on this mod:
https://vborg.vbsupport.ru/showthread.php?t=239710
OR
- Perhaps they just included a <img src="blah"/> type link as title instead of text.
OR
- You could use css to define a background image and also padding to show the image before, after, or as the entire tab so long as you set the width correctly.