Call-By-Name (CBL_) library and managed code

Is the Call-By-Name library available in managed code? Do the calls provide the same functionality? We have a "utility" native COBOL DLL program that uses several file handling CBL_ calls; CBL_CHECK_FILE_EXIST, CBL_COPY_FILE, etc. We are attempting to convert this program to managed code and during execution we are getting "file not found" errors. We use dd_xxx-style environment variables to define data file paths and "xxx\filename"-style file references in SELECT clauses. In the current test-subject solution an ASPX program calls a converted COBOL DLL that creates a "CNV\WYP46D01.098" on the path specified by the value of dd_CNV, but the converted "utility" COBOL DLL called by the ASPX program immediately after gets "file not found" (9/13) returned from CBL_CHECK_FILE_EXIST when the filename parameter contains the same "CNV\WYP46D01.098" value as the SELECT clause in the first COBOL DLL?