here the simpe code (im still learning regex for my future and sons)

$regex(c,[d-b])
how to make that code returning 1 WITHOUT changing [d-b]
so i want it goes like if (1 !ISNUM 2-4) { }
so far as i know,[d-b] mean d too b :
d,e,f,g,h,i,j,k,l,m,n,o,p,q,r,s,t,u,v,w,x,y,z,a,b so c is not include right
i hope someone help me


p/s : KINGTOMATO pls do not reply my post