Generally speaking, it should be possible to convert any 3D model in one format to its variant in other format. So it is likely you can convert XGL 3D CAD models (.xgl) to Collada 3D Digital asset file (.dae). The catch is to find a software that allows this model translation procedure and supports both these formats.
Convert XGL 3D CAD model to Collada 3D digital asset exchange data.
We found 3 software records in the database related to .xgl to .dae file format conversion.
Microsoft Windows software - convert xgl to dae on Windows
A CAD 3D geometry translation software
Convert from xgl file format
The tables with software actions are a good pointer for what a certain program does with various file types and often may give users a good hint how to perform certain file conversion, for example the above-mentioned xgl to dae. However, it is not perfect and sometimes can show results which are not really usable because of how certain programs work with files and the possible conversion is thus actually not possible at all.
A 3D CAD translation softwate
On-line services software - convert xgl to dae on web
A free online 3D model conversion service