How display part of a field in a combobox

what is the rowSource of the combo box?

Here is the SQL of the query:

SELECT tblProducts.ProductID, tblProducts.ProdRef, tblLocations.LocationDesc, Sum([IncomingQty]-[SoldQty]) AS [Inv Qty]
FROM (tblProducts LEFT JOIN tblLocations ON tblProducts.LocationID = tblLocations.LocationID) RIGHT JOIN tblInventoryDetails ON tblProducts.ProductID = tblInventoryDetails.ProductID
GROUP BY tblProducts.ProductID, tblProducts.ProdRef, tblLocations.LocationDesc
HAVING (((tblProducts.ProdRef) Like "*" & [Forms]![frmSearchForProductsOrImages]![cboProduct] & "*"))
ORDER BY tblProducts.ProdRef, tblLocations.LocationDesc;

And tblProducts.ProdRef is the field I'm trying to do this with.

try this

SELECT tblProducts.ProductID, Left([tblProducts].[ProdRef], InstrRev([tblProducts].[ProdRef],",")-1), tblLocations.LocationDesc, Sum([IncomingQty]-[SoldQty]) AS [Inv Qty]
FROM (tblProducts LEFT JOIN tblLocations ON tblProducts.LocationID = tblLocations.LocationID) RIGHT JOIN tblInventoryDetails ON tblProducts.ProductID = tblInventoryDetails.ProductID
GROUP BY tblProducts.ProductID, Left([tblProducts].[ProdRef], InstrRev([tblProducts].[ProdRef],",")-1), tblLocations.LocationDesc
HAVING (((Left([tblProducts].[ProdRef], InstrRev([tblProducts].[ProdRef],",")-1)) Like "*" & [Forms]![frmSearchForProductsOrImages]![cboProduct] & "*"))
ORDER BY Left([tblProducts].[ProdRef], InstrRev([tblProducts].[ProdRef],",")-1), tblLocations.LocationDesc;

Hmm that didn't work.  Now the combo box retuned nothing.

And if I just try to run the query I get the attached error.
error.jpg

create a function with a while loop incrementing a counter, character by character until there are no more commas, then return the counter and use it to derive right(string, len(str)-counter)

Thanks to all three of you.  I ended up using Rey's suggestion for timings sake but will keep record of the other two also.