Storing signature in Printer memory and accessing it in the sapscript

Hi Gurus ,

I have a requirement to upload signatures on to the printer memory (Its a HP 4250 printer for printing checks) and access the same to print them while printing the checks.

Please let me know the steps to achieve the following

1) Uploading the signatures to the printer and in which format - how should this be done.

2) How to acces the signatures in the printer in the sapscript form

Thanks

Rupendra