Need basic ESQL/C help

I'm VERY new to ESQL/C (though not new to C/C++) and have been unable to figure out some of the basic tenets of ESQL programming. For example, I wrote the following function: int dbalias (newname,oldname) $parameter char newname[40]; $parameter char oldname[40]; { EXEC SQL CREATE SYNONYM :newname FOR :oldname; return 1; } When I preprocess this code with the esql command, I get: esqlc: "dbio.ec", line 32: Error -33051: Syntax error on identifier or symbol ':'. I've included sqltypes (EXEC SQL include sqltypes;) to no avail. What do I need to do to get ESQL to recognize the fact that I want to insert the values of these variables? On a more fundamental level, when do I need to use the EXEC SQL prepare construct as opposed to the above method of direct insertion? Please email any insight to dcopeland@singular.com. Many thanks. - Dan