Select Top 1000000The magic is in the type conversion. Instead of adding tblAssetCustom.Custom1 to your report, add Cast(tblAssetCustom.Custom1 As float). Once you've got that, you can apply the aggregate functions to it.
Count(*) AS count,
Sum(Cast(tblAssetCustom.Custom1 As float)) As cost
Inner Join tblAssetCustom On tblAssets.AssetID = tblAssetCustom.AssetID
tblAssetCustom.State = 1
And IsNumeric(tblAssetCustom.Custom1) = 1
I'm with StevoCamaro: I don't see a cost field on the assets. You'll need to be more specific. Did you designate one of the custom fields for cost? If not, if there definitely is a cost field, can you identify the table it's in and, hopefully, the field name? Failing that, describe the page you're filling the value in on and where it sits relative to others, or possibly include a screen-capture.
I don't know of anything like in the report section, nor are there leasing cost/term/vendor fields for a report.
Purchase date is great, but without a capital cost value, how can you calculate the annual CCA on assets???
You could edit a custom field name on the asset page, enter the purchase value, then report on the custom field.