How can I pass the displayed value in a combo box to the WHERE clause of a SQL query in another combo box

This is the bit of code it gets stuck on€
With cd
Set .ActiveConnection = cn
.CommandText = "SELECT distinct(PONo) FROM POdata WHERE LCNo = ComboBox.cboLCNos.Value
.CommandType = adCmdTex
Set rst2 = .Execut
End Wit

I get an Automation error and it highlights €“ Set rst2 = .Execute €“
If I replace ComboBox.cboLCNos.Value with 'IMPLC3679' (a string in the LCNo field) it works
Thank you for any assistance you can give