Problem:
When generating a client in the Interface Mapping toolkit an error was displayed about a missing assembly MicroFocus.COBOL.CodeDom.
The error occured in Net Express V5.
Resolution:
Checking the Global Assembly Cache (c:\\windows\\assemblies) the file was indeed missing.
The issue was resolved by opening Add/Remove programs and highlighting Net Express. You can then click on the Support link and REPAIR the install.