Read Write cert

i have been reading a lot of previous threads on this forum and learning as much as possible about AT COMMANDS via UART using akseed no and reply but i have a problem that i am currently facing the problem is reading the cert from a phone via AT commands or box and then converting and Writing the cert via UART i have found everything online the only part that i havent found a clear explanation for is reading the cert and writing via UART using AT+IMEISIGN in QUALCOMM phones manly. i know some one who can read the cert from any QUALCOMM phones via combination file without root or anything i know i can read it via root using some boxes and dongle but some phones you cant accomplish root. so if anyone can you help me with the process i a have a lot of AT COMMANDS that i have been able to read from boxes and dongles DRK repair and stuff like that the only problem i have is reading the CERT and rewriting it after zeroing out the efs partitions and resetting the MSL so i can repair IMEI or accomplish something else via UPLOAD MODE ;)