[Bioperl-l] need help ??parse AcNum from fasta?

[outaleb Issame]

Hi every body,
i have some AccNum in a file-> IPI67675
                                                 IPI98976.
                                                 ...

what i want is how can i look in the fasta file (db fasta) if there is 
some match
if yes then copy the entire entry into a new fasta file.
i tried with bioperl but cause i m noob:-(( i don t get it.
thx all