WKT (well known text) files are used by GIS and related programs. Thanks to Jeremy Bender, LS-691, if you require such files he has created two text files covering the LDPs for the counties in Nebraska, one for the TM projections and one for the LLC projections. The projections for Lancaster County and Platte County are those designed by each county and were not designed by the State Surveyors Office. Find the county your are looking for in the TM or L1SP text file. Copy the entire line of text for that county. Save it into a text file. Change the extension of the file from "txt" to "wkt". Example name change, Gage LDP.txt to Gage LDP.wkt.
Also Jeremy has provided the following links to free coordinate converters
The first one is a free program that can be downloaded called, SeisWare Coordinate Converter.
The second is located online at a website called MyGeodata Cloud
The SeisWare Coordinate Converter will allow the use of the WKT. While MyGeodata Cloud will allow the input of coordinate systems in PROJ4 coding similar to QGIS. It should be noted that in the latest versions of QGIS utilize WKT (Prefered Method by QGIS) or Proj4 (Old Method) and can be copied and pasted into the Custom Projection dialog box.
Both the WKT and Proj4 formats are located in the spreadsheet.
All files available in WKT link above.