characteristic is not ALPHA -converted

In update rules (3.x) I am loading infoobject1 (NUMC 8) to infoobject2 (CHAR 10). Infoobject2 is of type ALPHA. At the time of loading I get the error characteristic is not ALPHA -converted. If I take out ALPHA from infoobject2 and load it, the load is proper. But the infoobject2 takes 8 digit values. I want 10 characters (preceeding 0). So in my opinion I can not remove alpha. What can be the solution?