Generating Sql String For Execution

I've a need to generate a condition clause (if statement) from 3 variables: a value, an operator & another value.

To generate this: 'abcd' like 'a%'
& verify if the condition is satisfied I've done the following:

CREATE TABLE #Temp(Result varchar(10))
declare @cond1 as varchar(50), @op as varchar(4), @cond2 as varchar(50),
@expr as varchar(50),@result as varchar(10)
set @cond1 = '''abcd'''
set @op = 'like'
set @cond2 = '''a%'''
set @expr = @cond1 + ' ' + @op + ' ' + @cond2
insert into #temp exec ('select case when ' + @expr + ' then ''true'' else ''false'' end')
if exists (select result from #temp where result = 'true')
select 'it is true'
else
select 'it is false'
drop table #temp


It works, but a bit clumsy. Is there a more elegant way to do this ?