I assume your mirc code is finding the incompletes and attempting to write to a batch file that will later delete (or do whatever) to those files.
I know the whole subject has long been discussed, far too much infact, so ill just suggest an alternative... try doing it all in a batch script.
Command prompts (and batch scripts) are far more powerful and useful that most people are aware of. In the simplest form, make the batch file that finds the files in question, does the checks required (if there are certain things such as crc that it cant handle then have it write to a temp file first, and have mirc signaled to check that file, do the tests, and remove the lines from the temp file... anyway...), writes said actions to the second dynamic batch file then runs it.
All you'd really need in mirc would be an alias to call the first batch file.
Since your already using batch files and the whole purpose is to perform an action that has nothing to do with irc or mirc, i dont see this 'alternate method' suggestion as being a cop out.
Hell if you post the code and explanation of the format/files that its finding/checking maybe it IS even possible to do in mirc without loosing the spaces.
