Forcing a DynamicText to appear inside the staff

[Thomas Weber]

Hi all,

in old orchestral scores one can observe that engravers did not hesitate to 
make more room in dense situations by moving dynamics into the staff rather 
than putting them below (or above).  To achieve the same effect, I tried the 
following:


{
  \once \override Staff.DynamicText #'X-offset = -4
  \once \override Staff.DynamicText #'Y-offset = 3
  c' \f
}


But Lilypond insist on keeping the dynamic outside of the staff.  I'm not an 
experienced Lilypond user, so I'm most likely missing something.  How can I 
achieve this effect?  (And are there counterparts to X-offset and Y-offset that 
allow specifying an absolute position?  At least staff-position does not seem 
to work.)

Thanks
Thomas W.