Hi Stephan
You could use mris_translate_annotation <subject> <hemi> <in annot> <translation file> <out annot>
with : *<subject>* : the subject you want to work on
*<hemi> *: the hemi you want to work on
*<in annot> *: your initial annotation file (ie the one containing Medial OFC, Lateral OFC, anterior part of the Cingulate)
*<translation file>* : a text file you have to create, that will list the labels( one per line) you want to group, and the new label you want to create. In fact you can't use the labels names but you have to use their RGB codes; each line will provide the input and output RGB values
for instance the following file 221 220 60 223 220 60 221 220 160 223 220 60 221 220 100 223 220 60
will group 3 labels (with RGB codes 221 220 60, 221 220 160, and 221 220 100) in a single label (223 220 60) you can get the RGB value by clicking view->information->annotation on tksurfer interface after loading the surface and the annotation file. Be carefull not to use a RGB code previously used in your input annotation.
You can get the RGB value of any label by clicking view->information->annotation on tksurfer interface after loading the surface and the annotation file. A field named annotation will be created on the interface with the RGV under brackets
*<out annot>* : the output annotation (the one you want to create, with labels grouped together)
cheers