Shared services msad

I need to lookup the users in our css_groups against MSAD.

I need to go from a sid from msad to the hyperion stored sid

The issue I am getting is that they are stored in this format

msad://OBJECTGUID=\xx\xx\xx\xx\xx\xx\xx\xx\xx\xx\xx\xx\xx\xx\xx\xx?USER

but msad is in the S-1-5-21-992878714-4041223874-2616370337-1001 format.

how can I convert my S-1-5-21-992878714-4041223874-2616370337-1001 to the msad://OBJECTGUID=\xx\xx\xx\xx\xx\xx\xx\xx\xx\xx\xx\xx\xx\xx\xx\xx?USER so I can lookup the users rights in hyperion from an external script?