Hello C S,
The CAPM OpenAPI tool is what you'd want to use to export data. Read about it here...
OpenAPI - CA Performance Management - 3.0 - CA Technologies Documentation
There is no function available at this time that allows direct import of data in the way you describe. We have supported Data Sources that can gather data from other tools like ADA, NFA, Spectrum, etc.
We also have our CAMM product that can import data from non-SNMP devices, but nothing for external data from, for example other DB's.
Hope that helps answer your questions.