As long as both of the CBC exercises are exactly the same (they have the same number of attributes, each attribute has the same number of levels, the text of each attribute and level is the same, the same number of CBC tasks, the same number of concepts per task, etc.) then you can export the CBC exercise data as a .CHO file from each of your studies.
To export from Lighthouse Studio (formerly SSI Web), choose "Data Management" from the "File" menu, and then click the "Export Data" tab. Click the "Add Job..." button, then click the "Add" button just below the Export Action list, then select the "CBC (.CSV, .CHO/.CHS, .ATT) option. Choose ".cho/.chs, .att" as the File Format.
The .CHO file is a text file that contains the design the respondent saw as well as the concept that he/she chose. You can then combine the two .CHO files from each of the studies by simply copying and pasting one of the two into the other using Microsoft NotePad. Make sure you paste at the bottom of the .CHO file with no blank lines. Finally, you can import the combined .CHO file into one of our analysis modules (like CBC/HB, for example) to estimate the utilities.