Recreate EA Strategy From Mql4 File with Bug / Error ! And Apply New Rules

I have an Expert Advisor in ex4 and mq4 file formats that I would like to recreate with its original strategy. I believe the file have a bug or one error inside  or maybe also is a Decomp file , and as a result, I am unable to understand the rules it follows to evaluate the market and open orders. I am looking for a developer who can help me reconstruct the strategy accurately.   The mql4 format file would need to be tested by compiling it into ex4 and compared with the ex4 supplied by customer. The delivered mql4 must produce the same results as the ex4 supplied by customer. If agreeable, pls let me know and I can send the Files for your assessment and we can talk about project !!