Normally UDO will replace all DOS graphic characters by the ASCCI characters "+", "-" and "|". So including DOS screenshots is not possible.
To display DOS screenshots you can use the linedraw environment, which is started with !begin_linedraw and finished with !end_linedraw.
No UDO commands (except !end_linedraw) or placeholders will be converted. Text inside this environment will be indented like normal text.
When converting into RTF, the font "MS Linedraw" will be used, other formats will use the DOS character set. When converting into LaTeX the commands of UDO will be just replaced by the LaTeX commands \begin{verbatim} and \end{verbatim}. When converting to another format UDO adjusts special chars and displays the text with a non-proportional font.
If the lines of the linedraw environment contain tabs (ASCII 9) UDO will replace them by spaces according to the !tabwidth setting.
Because no commands inside a verbatim environment are noticed you cannot use the !include command inside this environment.
To enable you to include an external file and display it as it would be inside a linedraw environment UDO offers you the command !ldinclude. This command is a mixture of !begin_linedraw, !include and !end_linedraw.
Please note: