One option could be to:
1) Create a data object to query the mdb for the system information, following are a few possibilities:
select machinename from al_cdb_componentinstallstate where packageid='task.install_slcm'
select value from usm_configuration where group_name='proxyconfiguration' and name='hostname'
select product_specific_data from ca_application_registration where product_name='CA Service Catalog'
2) Create a custom JavaScript function, invoked likely onLoad of the form, which calls ca_reportQuery to run the data object from step 1 and then hide/show the fields in the onSuccess function.
For information on ca_reportQuery as well as other predefined JavaScript functions I would recommend taking a look at Administration > Tools > Links > Form Designer JavaScript API > Global.