Context-free lexer for NM-TRAN

Hi all, Calling all computer scientists and computer language experts. In my spare time, I am working on a lexer and parser for NM-Tran. Primarly to teach myself about grammars and DSL, but perhaps something useful will come out of this (e.g. a context-sensitive editor with code completion). When lexing, I am having a hard time describing the keywords used by nm-tran. Let us take '.EQ.' as an example. 1) It seems that *.EQ. *is a keyword used to describe a comparison. 2) However, a filename could also be 'foo.eq.bar' The same thing applies for keywords on the '$ESTIMATION' record. These keywords could also be used as variable names. Am I right in saying that NM-TRAN cannot be tokenized with a context-free lexer? And that I should focus my efforts on building a lexer-less parser? (Or building my own lexer-parser, see https://en.wikipedia.org/wiki/The_lexer_hack ) I assume building a parser for NM-TRAN was already done in the DDMoRe project, but I failed to find the source code... Kind regards, Ruben Faelens