Is there an error message when you use the dimap file?
At least I see no obvious error in your batch file.
Another way of processing several files is using excel to create the batch file.
Copy the path the path to the files file in separate columns. For each pair of files you have now a row.
In the following columns you can specify the values of the parameters. In the last column you concatenate all columns to the command.
Because you can copy the values easily in excel, it is quite quick to create the commands.
The values of the command column can be copied in a batch file. A list of files names ca be retrieved in Windows ono the command line by calling:
dir /B > fileNames.txt
This will write all file names into the specified text file.