Decimal variable input with HSERIN command

[pxidr84]

Hello,

I would like to do a simple thing with the HSERIN command :

I send from my computer the ASCII chain "A1234". What I want it's to store the number (1234) in a variable (for instance, "vartest").
Also, if I send from my computer the ASCII chain "B0005", I want to store the number (5) into an another variable (let's say "vartest2").

I think it's quite simple, but I don't know how to handle that within a loop.

Thanks