survreg & gompertz

Hi all,

Sorry if this has been answered already, but I couldn't find it in the 
archives or general internet.

Is it possible to implement the gompertz distribution as 
survreg.distribution to use with survreg of the survival library?
I haven't found anything and recent attempts from my side weren't 
succefull so far.

I know that other packages like 'eha' and 'flexsurv' offer functions 
similar to survreg with gompertz support. However, due to the run-time 
environment were this needs to be running in the end, I can't use these 
packages :(

Same questions for the gompertz-makeham distribution.

Many thanks!

Matthias