regex - Regular expression alphabet, numbers - some character -

i forcing user write username based on rules follows:

   - alpha start    - alpha, numerals included    - exclude i, l , o, q, 0, 1, 7  

i tried [a-ha-hj-kj-km-nm-nnppr-zr-z2-689]

but know not or may wrong, suggest

please re should consider both smaller , capital case exclusion

this suit needs:

^[a-za-z&&[^iillooqq]][a-za-z0-9&&[^iillooqq017]]*$ 

[x&&[^y]] means "x not y"

edit: works in java @ least, since notation doesn't seem managed every regex flavor...