filter internal priming events in oligdT based Reverse transcription of 3'end library

Question

[linjc.xmu]

Hi. Is there any way to use samtools or bedtools to filter internal priming from BAM file? The principle is: within -10 nt and +10 nt window of the first base of unique mapped reads, if there has AAAAA (five continuous As or more than five As), this read should be filter out from BAM file. Thank you very much for your attention and help.