Thanks, Cetin. It's similar to my solution: (do you think, it would be better without using index on and seek?)
At the end of ChangeTown method:

with this.cboSelTowns
     .RowSource = ''
     .RowSource = m.lcSelect
     .requery()
	lnSelect = select()
	select curSwitchTowns
	index on town tag town
	seek m.tcTown
	.ListIndex = recno()
	select (m.lnSelect) 
endwith

>>Hi everybody,
>>
>>I have a combobox in a container class. Here is Container.ChangeTown method:
>>

>>lparameter tcState, tcTown
>>local lcState, lcSelect, lcTown
>>if vartype(m.tcState)<>"C"
>>   lcState=''
>>else
>>   lcState = m.tcState
>>endif
>>if vartype(m.tcTown)<>"C"
>>   lcTown=''
>>else
>>   lcTown = m.tcTown
>>endif
>>lcSelect=[select towns.fullname as city, towns.State, ] + ;
>>         [towns.ccode, postregn.joiningtwn as Town ] + ;
>>         [from postregn, towns where postregn.joiningtwn = towns.town ] + ;
>>         [and postregn.town = '] + m.lcTown + [' ] + ;
>>         [union select towns.FullName as city, Towns.State, ] + ;
>>         [Towns.ccode, Towns.town from Towns ] + ;
>>         [where town='] + m.lcTown + [' ] + ;
>>         [union select padr('< blank >',20) as city, space(2) as State, ] + ;
>>         [space(2) as ccode, space(4) as town from Towns ] + ;
>>         [where town='ACTO' ] + ;
>>         [into cursor curSwitchTowns order by 1]
>>with this.cboSelTowns
>>     .RowSource = ''
>>     .RowSource = m.lcSelect
>>     .requery()
>>endwith

>>
>>I'd like my combo to show passed town in DisplayValue (I actually pass Town, but the first field is City). How can I do it?
>>
>>Combo is not bound and should not be. It has empty ControlSource.
>>
>>Thanks a lot in advance.
>
>-Move town to first position
>*Init
>.Rowsourcetype = 3
>.Rowsource=m.lcSelect
>
>*ChangeTown
>Select curSwitchTowns
>locate for town=m.lcTown
>
>Cetin