First, determine if the DAZ content is available in both DAZStudio and Poser format. Current terminology standards describe them as DAZStudio Core and Poser Core. They should be installed into their corresponding applications. The same applies to Companion Files. Now, if the content is older and depending how it is packaged, installation would go directly into a Poser runtime.

Second, link your DAZStudio runtime to Poser's Content Library as mentioned above. This is important if the content is dependent on the DSON Importer. Nonetheless, a DAZ file and a Poser file must be installed for this to work.

Third, What OS are you currently using and where are your contents installed? If content is loaded into Program Files of specific Windows OS's then you have a bigger problem.

Fourth, consider that some DAZ content is only meant for DAZStudio and will not export over correctly.

Now, specifically, what content are you trying to export to Poser?