import re


def check_arg(arg_regs, opnd):
    """
    Check for argument register text in various possible formats
    :param arg_regs: list of argument registers
    :param opnd: operand to search for matches
    :return: register text if found in opnd
    """
    for reg in arg_regs:
        # if reg in opnd:
        m = re.search('[+*\[]'+reg+'[+*\]]', opnd)
        if m is not None:
            return reg
    return ""