_c2_ is a variable so you reference its value just like any other variable. In this case that means creating the attrib string using the concatenation operator.
[pre]
attrib='style={flyover="Lost: ' || _c2_ || '"}';
[/pre]
Now, regarding getting both style attributes at the same time. What's happening is that each call to the DEFINE routine with a style element
replaces any previously defined style elements. The last call always wins.
The solution, like so many solutions in this forum, depends on what version of SAS you're using. If you're using 9.2, PROC REPORT supports the "STYLE/MERGE" attribute.
[pre]
call define(_c4_, "style/merge", attrib);
[/pre]
"STYLE/MERGE" tells the DEFINE routine to
merge the style element with the existing style elements. With "STYLE/MERGE", the flyover attribute gets merged with the foreground attribute and so both are used.
If you're using an earlier version of SAS, you have to specify both the flyover attribute and the foreground attribute in the same call to DEFINE.
[pre]
attrib='style={foreground=red flyover="Lost: ' || _c2_ || '"}';
[/pre]
Here's the doc for STYLE/MERGE and its companion STYLE/REPLACE:
http://support.sas.com/documentation/cdl/en/proc/61895/HTML/default/a002473624.htm