my $blah = 'foo.Q';
print qq{gcc $blah -o @{[  substr $blah, 0, -2  ]} and many more };
__END__
gcc foo.Q -o foo and many more
[download]

See Re^2: How can we interpolate an expression??

See perlintro, perlrequick for the regex portion, and for the template, see (tye)Re: Stupid question (and one discussion of that template Re^2: RFC: Creating unicursal stars)

#!/usr/bin/perl --
#~ 2012-10-11-01:58:20PDT by Anonymous Monk
#~ perltidy -csc -otr -opr -ce -nibc -i=4     
use strict; use warnings;
use Data::Dump qw/ dd /;

Main( @ARGV );
exit( 0 );

sub getFiles {
    my @files;
    foreach (@_) {
        if( /\.[cC]$/ ){
            if( -e $_ ){
                push @files, $_;
            } else {
                printf "Unreadable file: %s : (%d) %s\n", $_, $!, $!;
            }
        } else {
            print "Invalid file: $_\n";
        }
    }
    
    return \@files;
}

sub compile {
    my $files = shift;
    for( @$files ){
## all of these do the same thing, see perlintro / perlrequick for exp
+lanation
#~       my( @cmd ) = ( 'gcc', $_, '-o', /^(.+?)\.[^\.]+$/  );
#~       my( @cmd ) = ( 'gcc', $_, '-o', $_ =~ /^(.+?)\.[^\.]+$/  );
       my( @cmd ) = ( 'gcc', $_, '-o' );
#~       push @cmd, $1 if /^(.+?)\.[^\.]+$/  ;
       push @cmd, $1 if  $_ =~ /^(.+?)\.[^\.]+$/  ;
       dd \@cmd;
       system @cmd;
    }
}


sub Main {
    return print Usage() if not @_;
    my $files = getFiles( @_ );
    dd $files;
    compile( $files );
} ## end sub Main


sub Usage {
    <<"__USAGE__";

$0    
$0    list of files to process


__USAGE__

} ## end sub Usage


__END__
[download]

If you're going to be using qx, you might want to quote/escape vars (like filenames) with String::ShellQuote