Without testing it by myself, try:
/TGBegin "Keyword"
/TGFindStr = "(?-i)^[ \t]*\*{0,1}(\u+)\>(?<!\<TITLE1)(?<!\<GRID)(?<!\<MODEL)(?<!\<ROCKFLUID)(?<!\<INITIAL)(?<!\<NUMERICAL)(?<!\<RUN)(?<!\<STOP)"
/TGEnd
With that modification the search starts at beginning of a line where 0 or more spaces/tabs can be found before finding 0 or 1 asterisk before finding an upper case word which is not one of the words in the following list.
/TGBegin "Keyword"
/TGFindStr = "(?-i)^[ \t]*\*{0,1}(\u+)\>(?<!\<TITLE1)(?<!\<GRID)(?<!\<MODEL)(?<!\<ROCKFLUID)(?<!\<INITIAL)(?<!\<NUMERICAL)(?<!\<RUN)(?<!\<STOP)"
/TGEnd
With that modification the search starts at beginning of a line where 0 or more spaces/tabs can be found before finding 0 or 1 asterisk before finding an upper case word which is not one of the words in the following list.
