Clinical trials and studies are increasingly using systems, such as REDCap, to capture data in electronic form. However these tools are not designed to mimic the capture of clinical information for regular clinical care and lack support for sharing the data effectively. In this paper we describe the implementation of a transformation engine, FHIRCap, that allows defining rules to map REDCap forms into FHIR resources. To assess the feasibility of the system, a case study with one of the Australian Genomics clinical demonstration projects was done. The case study showed that the transformation language is flexible enough to handle most of the data being captured in REDCap for a typical clinical trial. A number of design issues in the forms were identified and a series of recommendations were provided to enable a more accurate transformation. These results show that it is possible to transform most data in existing REDCap projects to FHIR resources without having to modify the forms. This is significant because it demonstrates that most data in existing clinical trials and studies can be made available in a standardised manner.