InvokeLookup return value question

SOLVED
I am trying to write a script that allows a user to press a button on the SO lines screen to call up the alias item numbers lookup, select a value, and then update a value on the line with a UDF from the selected alias item number. I am able to get the lookup to load, but I'm having an issue with the lookup only returning the itemcode rather then the full key for the alias item so I am unable to query the alias item object successfully. Is there anyway to control 
In the example below, if I press the button with a line with 1001-HON-H252 as the itemcode, I get the correct list of alias items in the lookup, but they all return just 1001-HON-H252 rather then 1001-HON-H252 +AliasItemNo+Type etc....
Is there a way to control what gets returned?
sLineKey = ""
sComment = ""
sItemCode = ""
sAliasItemKey = ""
sItemSeed = ""

set oLines = oBusObj.asObject(oBusObj.Lines)
r = oLines.GetValue("LineKey$", sLineKey)
sEditKey = oLines.GetEditKey(sLineKey)
r = oLines.EditLine(sEditKey)

r = oLines.GetValue("ItemCode$",sItemCode)
itemLength = oSession.AsObject(oSession.FileObj).GetColumnLength("SO_SalesOrderDetail""ItemCode$")
sItemSeed = sItemCode + String(itemLength - Len(sItemCode), Chr(0))
r = oUIObj.InvokeLookup("IM_AliasItemItem",sAliasItemKey,sItemSeed)
msgbox(sAliasItemKey)
Set oAlias = oSession.AsObject(oSession.GetObject("IM_AliasItem_bus"))
r = oAlias.Find(sAliasItemKey)
msgbox(cstr(r))