I want to use the g++ template in the "C" gcc software

Hi,
I create a C software and there is a requirement to use the g++ template *in* the gcc.
I do *not* want to use all the g++ "boilerplate" like special syntax, classes etc
I just want to use the template.
goal:
1. I already use "inline" code to replace "cpp-macro-like" syntax in the header.
2. NOW I *want* to replace a "cpp-macro" which use the *data-type* as an argument with a template.
question.
1. Is there a g++ switch to disable all the g++ features except of C source and template feature ?
2. Is there a gcc switch to add g++-template feature into gcc ?
3. is there an external software to add the c++-template feature into an existing C software ?
thanks.