userCertificate:certificateExactMatch: problem

[networm]

Hi! I use OpenLdap 2.39. I need to find the certificate with sn  
61a430c600000000000c and issuer email [EMAIL PROTECTED], but then i try  
this search:  
(userCertificate:certificateExactMatch:[EMAIL PROTECTED]), OpenLdap prints this error: filter=(?=undefined). I have understood that sn should be in dec form, but converting hex->dec not helped. How correctly convert sn in  
dec?