Format of HP 95LX file menu structure:
Offset	Size	Description	)
 00h	DWORD	pointer to ASCIZ base directory name
 04h	DWORD	pointer to ASCIZ file pattern (wildcard filespec)
 08h	DWORD	pointer to file list workspace, at least 1024 bytes (see #03283)
 0Ch	WORD	size of file list workspace in bytes
 0Eh	WORD	starting row (-3 is topmost, 0 is first non-"reserved" line)
 10h	WORD	starting column
 12h	WORD	number of lines
 14h	WORD	number of columns
 16h	WORD	number of files displayed on each line
---the remaining fields are initialized by the System Manager---
 18h	WORD	0000h if first edit character, else multiline
 1Ah	WORD	number of files in file list
 1Ch	WORD	max files workspace has room for
 1Eh	WORD	file at top of list
 20h	WORD	index of file to highlight
 22h	WORD	index of file to unhighlight
 24h	WORD	current focus (01h FMENU, 02h EDIT)