Gawk - Poundbang test is not working on WINDOWS

[U.Senthil Kumar]

Hello, 

I have involved porting gawk-3.0.5 from Unix to Windows but
I have problem in poundbang test case 

$cat poundbang
#! /tmp/gawk -f
        { ccount += length($0) }
END { printf "average line length is %2.4f\n", ccount/NR}

While running "make test" I got the syntax error for this 
patricular test case. 

I read from "CGYWIN" to rename gawk to gawk.exe in makefile, 
still it is failing. 

But this test is passing if I rename poundbang to poundbang.awk
Using "#!" i have tried for PERL, AWK and TCL .. I have got the 
same kind of error. Only file extension makes difference.

Very thankful to you if any one of you give me the solution 
for this "#!" problem. 

Why it is working if I rename the filename?.

Awiting for your reply ASAP.

Thanks in advance. 
Senthil