Dat file location can be defined using below configuration variables;
OVERHEADLINE_SICAT_SETTINGSDIR_DIR = $(CIVIL_ORGANIZATION_STANDARDS)Overheadline/OVERHEADLINE_SICAT_WORKSPACEDIR_DIR = $(CIVIL_ORGANIZATION_STANDARDS)Overheadline/OVERHEADLINE_SICAT_WORKSETDIR_DIR = $(CIVIL_ORGANIZATION_STANDARDS)Overheadline/
by default these variables are defined in the following configuration file (for metric workspace);
C:\ProgramData\Bentley\OpenRail Overhead Line Designer CE\Configuration\Organization-Civil\_Civil Default Standards - Metric.cfg
You can learn more about workspace setup for OpenX products below;
https://communities.bentley.com/products/road___site_design/w/road_and_site_design__wiki/36648/how-to-create-a-customized-network-workspace-environment
Example
Change Dat file location to D drive ProjectConfiguration folder;
OVERHEADLINE_SICAT_SETTINGSDIR_DIR = D:/ProjectConfiguration/OVERHEADLINE_SICAT_WORKSPACEDIR_DIR = D:/ProjectConfiguration/OVERHEADLINE_SICAT_WORKSETDIR_DIR = D:/ProjectConfiguration/