How to specify a library search path to configure's AC_CHECK_LIB?

[Schmidt]

I'm writing an application and want to make possible to compile it with or without an optional module. This module requires perl library to be compiled, so I want to check presence of it in 'autoconf'.
The problem exists because perl library is placed in 'non-standart' location itself (like a /usr/lib64/perl5/CORE/libperl.so). So when I try to run configure (with AC_CHECK_LIB or AC_SEARCH_LIBS), it cannot find and link libperl.so in its test. Trying to pass

./configure CFLAGS=-L/usr/lib64/perl5/CORE/

or

./configure LDFLAGS=-L/usr/lib64/perl5/CORE/

does nothing. How can I define a location to search for configure's tests?

[Schmidt]

I found how to pass a library path in '--with-module=<PATH>', but how I make AC_CHECK_LIB to use it?...