Replace if x and y is the same..

i need something that
for example

if value of %genre% is the same with value "rock" then must displayed value "1",
if not,then should not output it,but if %genre% is the same with "metal" then should display "2"
how is possibly to realize it?
Thank you very much!

I found the solution in the documentation!thank you for programm! who same need it,look code..

$if($eql($trim(%GENRE%),'alternative'),1,) $if($eql($trim(%GENRE%),'rock'),2,) $if($eql($trim(%GENRE%),'metal'),3,) ... or ... $if($stricmp($trim(%GENRE%),'alternative'),1,) $if($stricmp($trim(%GENRE%),'rock'),2,) $if($stricmp($trim(%GENRE%),'metal'),3,) ... or ... $regexp('/alternative/1/rock/2/metal/3/','^.*/'$trim(%GENRE%)'/(\d+)/.*$','$1',1)

DD.20131214.1059.CET, DD.20150218.1738.CET