Use the EL functions from tc:format1 to tc:format9 to replace up to 9 variables in a given internationalized text. This work like in java.text.MessageFormat.
tc:format1
tc:format9
The message format is: "The equatorial radius of the sun is {0} km."
<tc:out value="#{tc:format1(format1text, 695700)}"/>
The message format is: "The temperature of the sun is {0} K on the surface, but {1} K in the center and {2} K in the corona."
<tc:out value="#{tc:format3(format3text, 5800, 15700000, 5000000)}"/>
The message format is: "Just reordering: {4} - {1} - {6} - {8} - {5} - {3} - {0} - {7} - {2}"
<tc:out value="#{tc:format9(format9text, 0, 1, 2, 3, 4, 5, 6, 7, 8)}"/>
You may also use the fn: function library for string manipulation.
fn:
<tc:out value="#{fn:toUpperCase('uppercase')}"/>