Fix2Ged is a DOS program written by the LDS Family History Department in 1993, but still works.
This utility was developed so that the user could use a grammar pattern file to describe the fixed field (field delimited) input file, as well as defining the appropriate GEDCOM structure in which the specified fixed fields are to be mapped. This program will not provide linkage of relationships.
The Fixed Field to GEDCOM Conversion Utility uses a GEDCOM processor and a GEDCOM grammar pattern file to convert the field delimited file into a GEDCOM output. The fields in the field delimited input file are usually variable length, separated by a field delimiter, but they can fixed length as specified by the GEDCOM grammar pattern file.
The GEDCOM Processor reads in the input fixed file and parses the record into fields as specified by the define record structure from the GEDCOM grammar file. The GEDCOM portion of the grammar file is traversed to determine the mapping from the fixed field input file to the desired GEDCOM output structure. Function call directives are placed within the GEDCOM grammar file to initiate this mapping. The GEDCOM processor will call these functions to retrieve the fixed field values and then places them in the GEDCOM output structures. The output structure is written when all of the nodes in the GEDCOM pattern file have been visited and populated with the fields from the input file. (Details from PAF Review)
The program can be downloaded from http://pac-its.psu.edu/genealogy/gedcom/demo.zip. The program and documentation is contained ion the zip file.