replace character on server side

Driver

What is the best way to replace characters on server side?
Now I have a condition:
[code]$element_26 = 'CASE WHEN (element_26 = 1) THEN "value1" WHEN (element_26 = 2) THEN "value2" WHEN (element_26 = 3) THEN "value3" WHEN (element_26 = 4) THEN "value4" WHEN (element_26 = 5) THEN "value5" WHEN (element_26 = 6) THEN "value6" WHEN (element_26 = 7) THEN "value7" WHEN (element_26 = 8) THEN "value8" END';[/code]
But this works only when I have max six conditions. Please help.