I posted the same question at DevX's VB-ZONE and somebody replied to me this:
"The DataFormat is used in conjunction with databases, along with DataSource,
DataMember, and DataField. Read up on all of these." I already set-up the dataformat to number along with comma but running the module, it doesn't work as in if I type a character it accepts it; no comma appearing. In VFP, it's no sweat. Once you initialize the textbox into zero, it will return and only accept numeric entries... Ehhhhhh....