I don't know enought scid but if you have 2 differents names in the header I don't think it is possible.
If you don't have too much games with differents capital names perhaps save/replace and change the name in the header. Or save the base in a .txt and change using word (find and replace to be faster) then import in scid to save a .png again.
I keep a dbase of all my old games and they are arrainged according to my opponent's name. The problem is that there are actually two lists. SCID alphabetizes all the uppercase A-Z and then lower case a-z. Does anyone know if this can be changed so there is only one list?