[amibroker] Yahoo Symbols

[tipequity]

I have a list of stocks that trade on over the counter and pink sheets. 
Yahoo assign a .ob and .pk to the underlying symbol (e.g., CHRZ becomes 
CHRZ.PK). Is there an easy way to get these extensions for the 
undelying stocks symbols? My list looks somthing like the following:
ABLE
BUTL
CHRZ
CLST
.
.
.