I don't use mxLoader, others on my team use that tool. But I format the data and send it to them to similar requirements every few weeks.
You will need to know the Classification Name and then write a query / report to make this data in Excel. This will start you off. We use Oracle but I try to write everything in ANSI standard SQL. Something like this, replacing X with the SiteID and Y with with OrgID if needed.
Locations and the current Classification:
Select Locations.SiteID,
Locations.Location,
Locations.Description LocDesc,
Classification.ClassificationID,
Classification.Description ClassDesc
From Maximo.Locations Inner Join Maximo.ClassStructure
On Locations.ClassStructureID = ClassStructure.ClassStructureID
Inner Join Maximo.Classification
On ClassStructure.ClassificationID = Classification.ClassificationID
Where Locations.SiteID = 'X' and
Locations.OrgID = 'Y'
Current Spec Values:
Select Locations.SiteID,
Locations.Location,
Locations.Description LocDesc,
Classification.ClassificationID,
Classification.Description ClassDesc,
LocationSpec.AssetAttrid,
AssetAttribute.Description AssetAttridDesc,
LocationSpec.ALNValue,
LocationSpec.NumValue
From Maximo.Locations Inner Join Maximo.ClassStructure
On Locations.ClassStructureID = ClassStructure.ClassStructureID
Inner Join Maximo.Classification
On ClassStructure.ClassificationID = Classification.ClassificationID
Inner Join Maximo.LocationSpec
On Locations.SiteID = LocationSpec.SiteID and
Locations.Location = LocationSpec.Location and
Locations.ClassStructureID = ClassStructure.ClassStructureID
Inner Join Maximo.Classification
On ClassStructure.ClassificationID = Classification.ClassificationID
Where Locations.SiteID = 'X' and
Locations.OrgID = 'Y'
PS: Not sure why but copying and pasting from this website gives me invalid characters so you might need to send it through something like notepad first.