The modification in this case would be to add tblassets.assetname Like 'BRSP%' to the Where clause of the report. We've pasted the adjusted version below.
Select Top 1000000 tblAssets.AssetID,
tblAssets.AssetUnique,
tblAssets.Domain,
tsysOS.OSname,
tblNetwork.Description As [Network Card],
tblNetwork.MACaddress,
tsysOS.Image As icon,
tblNetwork.IPAddress,
tblNetwork.Lastchanged
From tblAssets
Inner Join tblNetwork On tblAssets.AssetID = tblNetwork.AssetID
Inner Join tblAssetCustom On tblAssets.AssetID = tblAssetCustom.AssetID
Inner Join tsysOS On tblAssets.OScode = tsysOS.OScode
Where tblNetwork.IPEnabled = 1 And tblAssetCustom.State = 1
And
tblAssets.AssetName Like 'BRSP%'Order By tblAssets.AssetName