Expanding a macro into quotes in `m4`

In m4, is it possible to expand a macro and to immediately put it in quotes? That is, instead of define(HELLO, `Hello!')dnl define(MACRO, `HELLO')dnl MACRO expanding to Hello!, I would love to have some function qexpand, for example, such that define(HELLO, `Hello!')dnl define(MACRO, `HELLO')dnl qexpand(`MACRO') expands to HELLO. But any other line after the first two that expands MACRO into a string would do as well, of course. --- *Background*. I want to operate substitutions on the expansion of a macro using patsubst, say substituting commas in it. Unfortunately define(MACRO',x,y,z')dnl patsubst(MACRO',,',`.') yields x,y,z, as the substitution is performed on the string MACRO. But if the expansion of the macro contains commas, the variant define(MACRO',x,y,z')dnl patsubst(MACRO,,',.') has the second line first expand to `patsubst(x,y,z,,',.'), giving the error Warning: excess arguments to builtin patsubst' ignored``. The possibility of expanding a macro into quotes would solve this.