Are there escape & evasion files of men who escaped during forced marches

Not sure if this applies directly to your search but the National Archives Catalog has a series "Escape and Evasion Reports, 1942 - 1945" in Record Group 498: Records of Headquarters, European Theater of Operations, United States Army (World War II), 1942 - 1947, which contains a number of scanned Escape and Evasion reports.  However, those reports that are available online appear to be almost entirely from downed aircrew who escaped from enemy-occupied territory, as opposed to POWs who escaped after being captured.

Example of 1 page from the Escape and Evasion Case File for Flight Officer Charles (Chuck) E. Yeager:

Dear Val Burgess,

Thank you for posting your question on History Hub!

We searched the National Archives Catalog for any escape and evasion files that might be of interest to you.  The search produced the following results. 

Please note that the entire series titled “Escape and Evasion Reports” in the Records of Headquarters, European Theater of Operations, United States Army (World War II) (Record Group 498) has been digitized. The digital images of the records can be viewed here.  Unfortunately, we were not able to locate a file for an individual named “Cleven.”

Also, we looked into the “European Name Index to the Series ‘Case Files, 1944-1949’” in the Records of the Office of the Judge Advocate General (Record Group 153).  We located an index card for “Cleven, Maj. G.W.” referencing case number “100-474” and providing the following summary “Improper sanitary conditions, housing, and food preparation at Stalag XIII D, Nurnberg, Germany 4 Jul 43 to 9 Apr 45; (8-45).”  The file “100-474” referenced on this index card is located in the series titled “Persons and Places Dossier Files.” 

In addition, you might want to review records filed under decimal “383.6” (Prisoners of War) in the series titled “General Correspondence, 1944-1945” in the Records of Allied Operational and Occupation Headquarters, World War II (Record Group 331) as they may contain some information on evacuation marches.

The staff of the National Archives at College Park - Textual Reference (RDT2) will be pleased to make the finding aids to these records available to you or your representative in the Textual Research Room located 8601 Adelphi Road, College Park, MD, near the University of Maryland--College Park campus. The Textual Research Room (Room 2000) hours are 8:45 a.m. to 5:45 p.m., Monday through Friday, except legal holidays. The RDT2 consultation room hours are 8:45 a.m. to 4:00 p.m., Monday through Friday, except legal holidays. No appointment is necessary. Prior to your visit, please consult College Park websites at https://www.archives.gov/dc-metro/college-park/,  https://www.archives.gov/dc-metro/self-service-copying.html, and https://www.archives.gov/research/start/getting-started.pdf.

We hope this information is helpful.  Best of luck with your research!