Changing font tag for BaseFont

[Robert Strauch]

Hello,

I have a PDF which embeds a TrueType font called UnicodeDoc. Within the 
PDF I can see the following:

/BaseFont /IKOTCH+UnicodeDoc

Is it possible using PDFBox to change the tag value IKOTCH and if so 
how? I know that this value may be different for other documents. 
However I just need acces to this tagbut I cannot find the appropriate 
way.

Sincerely,
Robert