Search record via primary key and use another field to filter

[netpatnet]

We are using Peregrine Assetcenter (SQL Database) and Crystal Report v7 together. In the database we have a location-table with locations, sub- and sub-sub-locations etc.

---- Sub-Location
|
Location |--- Sub-Location --- Sub-Sub-Location --- ....
|
---- Sub-Location

We are searching for a solution, how to build a CR report which is printing a location with all the the sub-locations (unlimited level) underneath.

The Assetcenter is "only" giving the unique ID ({@amLocationId}) of the highlighted location as parameter to CR. Every location-record contains a field with the unique ID ({amLocation.lLocaId}) and a field ({amLocation.lParentId}) with the parent location. The filter we are currently use is looking as follows:

({amLocation.lLocaId} = {@amLocationId} or
{amLocation.lParentId} = LocId)

With this filter CR is showing the location and the 1st level of sub-locations, but deeper levels (sub-sub-locations etc.) is not showed.

Is it possible to locate a record via the filter {amLocation.lLocaId} = {@amLocationId} and use the value of another field of the found record as the report-filter?

Example:
1.)
Search location-record with filter {amLocation.lLocaId} = {@amLocationId}

2.)
Use value of {amLocation.FullName} of found record to find all sub-location-records

btw: Our report already uses subreports.
btw2: In Assetcenter it is not possible to send the FullName-field as paramter to CR. Only the primary key is possible to send.

Thank you very much for any hint.