giving path to system linker without microsoft tools

What product version are you using?
Are you receiving an error?

The Microsoft Tools are installed automatically by the Visual COBOL installer.

If you need to change the version that Visual COBOL will use you can do so using the cblms utility which is documented here.

cblms can also tell you which versions are installed and which are in use:

cblms -Q will display the versions of the SDK and Built Tools that are currently in use.
cblms -L will display all the versions that are currently installed in default folders.